## How to Solve Input Output in Reasoning Questions

In IBPS exams we can accept input output questions in logical reasoning section From the Input- Output section good number of questions have been asked in previous IBPS exams and also in RRB exams . We can accept nearly 5 questions based on input output series method. So understanding the concept of input output series method is very important

In this input output method we are supposed to imagine that input is fed to machine . Machine process the input and arrange the input in each step

and produce the final output in the final step We have to determine the pattern and based on that solve the questions. A word and number arrangement machine when given an input line of words and numbers rearranges them following a particular rule in each step to produce final output

In this machine arrangement can be of following types

1) Numeric numbers arranging in decreasing order in each step

2) Words arranging in alphabetic order from A-Z

3) In series there is both numeric and alphabetic words, so in one step number is arrange in decreasing order and in other step word is arrange in alphabetic order from A-Z.

4) Number can be arrange by odd and even numbers. Odd numbers are arrange in decreasing order than even number in decreasing order.

5) Words are arrange in alphabetic order in extreme left and numbers are arrange in decreasing order at extreme right in each step

6) First words are arrange in alphabetic order than numbers are arrange in decreasing order.

We have given few examples which help you to better understand the input output questions

### Problem :1

Q:- An Input /Output device arranges numbers step-by-step in a particular order according to a set of rules. The device stops arranging the numbers when the final result is obtained. –

Input- 94 65 35 100 54 69

Step 1 100 94 65 35 54 69

Step 2 100 94 69 65 35 54

Step 3 100 94 69 65 54 35

As per the rules followed in the above steps, find out in each of the following question the appropriate steps for the input given below :

Study the above arrangement carefully and give the answer to the following question –

What is the last step of the input given below?

8 70 90 17 35 40

**Solution :**

Based on the above series find the last step of the given arrangement. You will easily find out that the numbers are arranged in descending order. In the step 1 higher number i.e. 100 is arranged come first , only one element in each step is arranged .Than in step 2, 94 is already arranged so 69 which is third highest number comes and so on .

**Following these steps we have to find steps required to completed the above arrangement**.

*Input 8 70 90 17 35 40*
Step1 90 8 70 17 35 40

Step2 90 70 8 17 35 40

Step3 90 70 40 8 17 35

Step4 90 70 40 35 8 17

Step5 90 70 40 35 17 8

Answer: So 5 steps are required to complete the given arrangement . and from above we can tell last step i.e. 90 70 40 35 17 8

###
**Problem :2**

**Q:**A word and number arrangement machine when given an input line of words and numbers rearranges them following a particular rule .Following is the illustration of input and rearrangement

**Input : lock come apple them done square**

Step1 apple lock come them done square

Step2 apple come lock them done square

Step3 apple come done lock them square

Step4 apple come done lock them square

Step5 apple come done lock square them

As per the rule followed in the above steps find out in each of following questions the appropriate steps for the input given below

**Input: hand sand major your watch action**

**Q:1**How many steps would be needed to complete the arrangement

**Solution :**From the above input output series we have to carefully see the pattern how the words are arranging in each step .Based on that we have arrange the words in each step and get final output .As in above pattern words are arranging in alphabet order A-Z in each step. So we can get final output based on that

**Input: hand sand major your watch action**

Step1 action hand sand major your watch

Step2 action hand major sand your watch

Step3 action hand major sand watch your

**As in step2 hand is already arrange in alphabet order so we arrange the next word in alphabet order in same step**

**So THREE steps are required to complete the given arrangement**

###
**Problem :3**

**Q:**A word and number arrangement machine when given an input line of words and numbers rearranges them following a particular rule in each step. The following is an illustration of input and rearrangement.

**Input:**

*gone name 43 39 18 for again 66***
**

**Step 1 :**66 gone name 43 39 18 for again

**
**

**Step 2 :**66 again gone name 43 39 18 for

**
**

**Step 3 :**66 again 43 gone name 39 18 for

**
**

**Step 4 :**66 again 43 for gone name 39 18

**
**

**Step 5 :**66 again 43 for 39 gone name 18

**
**

**Step 6 :**66 again 43 for 39 gone name 18

**
**

**Step 7 :**66 again 43 for 39 gone 18 name

As per the rule followed in the above steps find out in each of following questions the appropriate steps for the input given below :

·

**Input:***their 19 27 dent are 91 hour zero 31 16 chairs.*
Which of the following will be step 4 ?

A) 91 are 31 their 19 27 dent hour zero 16 chairs

B.) 91 their 19 27 dent are hour zero 31 16 chairs

C.) 91 are 31 chairs their 19 27 dent hour zero 16

D.) 91 are 31 chairs 27 dent 19 their hour zero 16

**Solution 1 :**From the above arrangement pattern we find that it consist of two series the numeric number series and alphabet series . The numeric numbers are arranged in decreasing order and alphabet are arranged with first alphabet of every word from A-Z alphabet which appear first to lower down in series and in one step number is arranged and in other step a word is arranged .

**Input:**

*their 19 27 dent are 91 hour zero 31 16 chairs*
Step1 91 their 19 27 dent are hour zero 31 16 chairs

Step2 91 are their 19 27 dent hour zero 31 16 chairs

Step3 91 are 31 their 19 27 dent hour zero16 chairs

Step4 91 are 31 chairs their 19 27 dent hour zero 16

Step5 91 are 31 chairs 27 their 19 dent hour zero 16

Step6 91 are 31 chairs 27 dent their 19 hour zero 16

Step7 91 are 31 chairs 27 dent 19 their hour zero 16

Step8 91 are 31 chairs 27 dent 19 hour their zero 16

Step9 91 are 31 chairs 27 dent 19 hour 16 their zero

So from above arrangement we can tell what the possible arrangement in step 4

**Answer –C**

**2.Which of the following would be final arrangement ?**

A) 91 are their 27 19 dent hour zero 31 16 chairs

B) 91 are 31 chairs 27 dent 19 hour 16 their zero

C) 91 are 31 chairs 27 19 dent hour 16 their zero

D) 91 are 31 chairs 27 dent 19 zero hour 16 their

**Answer – B , We can easily find out the step four from the above.**

**3.Which of the following would be the Step 1 ?**

A) 91 their 19 are 27 dent hour zero 31 16 chairs

B) 91 are 31 chairs 27 dent 19 hour 16 their zero

C) 91 are 31 chairs 27 19 dent hour 16 their zero

D) 91 chairs are 31 27 dent 19 zero hour 16 their

E) Non of these

Answer : E) Non of these .As none of given options matches with Step 1

### Problem: 4

**Q:**A word and number arrangement machine when given an input line of words and numbers rearranges them following a particular rule in each step. The following is an illustration of input and rearrangement

Input: sap 28 have 18 99 48 luck nice 78 ramp

Step1 have sap 28 18 48 luck nice 78 ramp 99

Step2 luck have sap 28 18 48 nice ramp 99 78

Step3 nice luck have sap 28 18 ramp 99 78 48

Step4 ramp nice luck have sap 18 99 78 48 28

Step5 sap ramp nice luck have 99 78 48 28 18

*Input: 49 late zen 15 82 yet can vast 33 alt 87 54*

*Q:1 How many steps would be needed to complete the arrangement?*
1) IV 2) V 3)VI 4)VII 5)Non of these

**Solution**: From careful analysis of the given input , various steps of rearrangement in step 1 word which will appear first in dictionary is placed at extreme left position and highest number is placed in extreme right position . In step 2 word which appear second place in dictionary is placed at extreme left and second highest number is placed at extreme right .same is followed in all next steps

*Input: 49 late zen 15 82 yet can vast 33 alt 87 54*
Step 1 alt 49 late zen 15 82 yet can vast 33 54 87

Step2 can alt 49 late zen 15 yet vast 33 54 87 82

Step3 late can alt 49 zen 15 yet vast 33 87 82 54

Step4 vast late can alt zen 15 yet 33 87 82 54 49

Step5 yet vast late can alt zen 15 87 82 54 49 33

Step6 zen yet vast late can alt 87 82 54 49 33 15

*Answer : 3) VI*

*Q2:Which step number would be the following output :*

*Vast late can alt zen 15 yet 33 87 82 54 49*
1) III 2)II 3) VII 4)IV 5) None of these

*Solution : From the above series we can find out which is the step*

*Answer : 4 ) IV*

*Note understand yet!!!!*

One of the most scoring questions in any Banking exam is Input-Output. These questions look tough and often take up huge chunks of your valuable time in solving. With the SBI PO prelim paper brought down to 1 hour duration, it is of vital importance that these questions be solved quickly. Learning short tricks to handle these types of questions will significantly boost your reasoning score.

Be warned, this method looks tougher than it is. You will need to sit down with a pen and paper to understand this one. But it is truly an easy method. Once you grasp it, you can cut down your time spent on input-output questions to less than a quarter of what you used to. If earlier you spent 8-10 minutes trying to solve 5 input output questions, you can now solve them in 2 minutes! Isn’t that amazing? So all we ask for is patience while you read on.

__WHAT IS INPUT OUTPUT__Machine input or Input Output is a question type, where the candidate is given some kind of word and number arrangement. With each subsequent operation, the arrangement of the words and numbers changes. These operations are performed until a final arrangement is reached or is performed in loop. The student is required to identify the hidden pattern in the rearrangement and apply it to the questions.

__Example:__- A word arrangement machine when given an input of words, rearranges them following a particular rule in each step. The following is an illustration of input and steps rearrangement.

This is the final arrangement and STEP IV is the last step for this input.

What should be the last step of the following input?

**INPUT: Coal Steer Brief Nap Blast Cry**

**Explanation:**The given rearrangement has a pattern that can be followed from the input step to the final step, which is Step IV. Observe carefully. The rearrangement follows the following patterns:

- The rearrangement is taking place from left to right.
- The rearrangement is taking place one word at a time.
- The rearrangement is done on the basis of decreasing alphabetic order.

**NOTE:**To understand the pattern, often it is sufficient to look at the input, 1st, 2nd and final steps of the arrangement.

Now if we apply the same pattern rules to the second input given, we can immediately tell what the output (final step after rearrangement) would be:

INPUT: Coal Steer Brief Nap Blast Cry

OUTPUT: Steer Nap Cry Coal Brief Blast

__TYPES OF QUESTIONS__
This was a simple example involving only words. Some questions come with only numbers. Others come as a mix of words and numbers. More complicated ones may even involve symbols. But for the sake of the Bank PO exams, it is important to concentrate on the questions that are mixes of words and numbers.

Based on the logic used behind the rearrangement, we can classify these types of questions as:

**A. Rearrangements based on Ordering:**

Words are arranged alphabetically (forward or reversed) as per their positions in the dictionary while numbers are arranged in ascending/descending order.

Both words and numbers could be arranged individually or simultaneously in each step. The rearrangement can start from the leftmost side or the rightmost side of the sentence and sometimes even simultaneously from both the ends. The rearrangement could either start with a word or a number. Whatever the finer details may be, in these kinds of rearrangements, one or two words/numbers are shifted at a time, without changing the order of the remaining words/numbers.

Here, Step III is the final step and the rearrangement is done simultaneously from both front and back ends. The rearrangements are done thusly: the numbers are arranged in ascending order one by one from the left end, with the next biggest number being added to the right of the previous number. The words are arranged in descending order one by one from the right end, with the last word in the dictionary going to the rightmost end, and earlier entries in the dictionary getting added in subsequent steps to the left of that word.

**B. Rearrangements based on Interchanging the Positions of Words and Numbers:**

Specific positions are selected and the positions of only those words/numbers are exchanged. The positions of all others remain unchanged.

Step VII is the final step of the input. The underlined words are used to indicate the words that will be interchanged in the each subsequent step.

**C. Rearrangements based on Mathematical operations:**

Some mathematical operation (like squaring the number, adding the digits within the number, some common number added/subtracted/multiplied/divided to each number etc.) is applied on the numbers in each step.

Step III is the final step. Clearly in this example, the unit’s digits of the left most and right most number are simultaneously being subtracted from the numbers themselves. This is followed by the number to the right of the left most one, and to the left of the right most one.

__TIPS ABOUT NUMBER OF STEPS__- If there are ‘n’ words/digits in the input then at most ‘n-1’ steps are required to rearrange it completely.
- Number of words/digits arranged until the present step is greater than or equal to the present step number.
- If input is not given we cannot determine the previous step from given step number or we cannot determine input from given step number.

__HOW TO SOLVE__
These questions can be solved by the following methods:

1. We can solve these questions by writing each step of the given input on paper.

**Remember**– do not write the complete word each time; to save time, just write the first letter or however many letters of each word you need to uniquely identify it.

__Example:__**Input:**32 pure girl beautiful 49 63 78 random rickshaw

**Label:**32 P G B 49 63 78 Ra Ri

2. We could go for a shorter method where instead of writing each step again and again we number each word/number of the input as per their position in each step. So if the arrangement follows a “number-descending-from-left-and-letters-ascending-from-right-alternately-pattern”, we need to number these as follows:

Clearly the pattern is, ‘send the biggest number left’. In the next step, send the highest word right. Continue the pattern till the input is completely rearranged.

To minimize the steps, let us look at all the elements on the basis of their positions. We only need to see the first two steps and the output to figure out which number/word goes where. The order in which the element gets rearranged is the number each element gets.

**INPUT:**32 pure girl beautiful 49 63 78 rickshaw random

**LABEL:**7 6 8 9 5 3 1 2 4

Since ‘78’ is the first element that will be rearranged according to the pattern, it will be labeled 1. The next element to be rearranged will be ‘rickshaw’. So it will be labeled 2. The next element to be rearranged will be the next highest number. So without even writing out the remaining steps you could label ‘63’ as 3. And similarly ‘random’ would become 4. And so on and so forth.

While rearranging by this method, keep the following four cases in mind:

**When we go in single direction, i.e. words/digits are arranged either from left to right or right to left. In this case,**

__Case 1:__**auto filling**of words/digits could take place because some numbers/words arrange themselves. So how do we go about numbering our elements in this case?

**For convenience’s sake, let us think of all the elements being arranged left to right.**

- Number each word/number in the manner shown above as per their order of arrangement in accordance with the pattern depicted in the question. Think of it as a step-by-step process. After each numbering, you need to stop and check.
- After you identify the first element, number it (1). Then identify the second element. Check all the elements to its left. Have you numbered all of them yet? If yes, then number this one (1a). If not, then number it (2). Then identify the third element. Check all the elements to its left. Have you numbered all of them yet? If yes, then this does not get a new step number. If no, then it gets a fresh step number. And the process continues. Here is an illustration.

Step VII is the last step of the input

**Q**. Following the above pattern, how many steps will be required to complete the arrangement for the below given input?

**84 out sown even 35 54 around 46**

**Solution:**

**Input:**In the given illustration, the words/digits are being arranged in the following manner: the lowest digit is arranged at leftmost of the sentence and all others are shifted to the right side as it is and in second step, highest word of dictionary is arranged right of the previously arranged number and so on. The next higher digit and next highest word is arranged in subsequent pair of steps.

Here is how you would go about numbering these elements. Note that underlined elements represent those ones to the left that you haven’t numbered yet.

Here, 6a and 6b are not given further values at the time of filling, as all elements to the left of these two have been filled already. Hence, these two entities are arranged automatically in step 6. In addition, step 6 is the last step of the input, so six steps are required to complete the arrangement.

**Now whichever step is asked in the question, take the part of the solution up to the required step number to get the answer. Arrange the numbered elements according to their labels, and shift the remaining to the right, while leaving their order unchanged.**

__NOTE:__**If the rearrangement is to be done from the right, the process of checking would be reversed. Now instead of checking to the left, you would have to check to the right to see if there are any unnumbered elements.**

__NOTE:__**When we go in both directions, with elements filling in from the inside,**

__Case 2:__**auto filling**could still take place. So we need to take that into account when numbering. Based on which direction the element goes, it is numbered with an L (left) or an R (right) attached to it. When considering items labeled with L, check to see if there are any unlabeled elements to its left and when considering items labeled with R, check to see if there are any unlabeled elements to its right.

Step III is the final step of the rearrangement.

Q. Following the above pattern, how many steps will be required to complete the arrangement for the below given input?

**goat out 34 59 set 75 peon 28**

**Solution:**

**Input:**The rearrangement clearly happens from both directions simultaneously, but from the inside. The fact that the rearrangement is happening from the inside makes a huge difference. The numbers are arranged in ascending order from the left and the words are arranged in descending order of their appearance in the dictionary, but from the right.

Here is how you go about numbering these elements. Note that underlined elements represent those ones to the left of the ‘L’ elements that you haven’t numbered yet. And the italicized elements represent the ones to the right of the ‘R’ elements that you haven’t numbered yet.

Now, it is easy to answer the question based on the numbering. The answer is three steps.

Q. Following the above pattern, what will be the second step after rearrangement for the below given input?

**goat out 34 59 set 75 peon 28**

**Solution:**

The underlined elements represent the remaining elements unchanged in order.

**When we go in both directions with elements filling in from the outside, i.e. we place digits/numbers left to the left most word/ right to the right most word. In this case,**

__Case 3:__**no**

**auto filling**of digits/numbers takes place i.e. each word is numbered separately. Keep in mind the following:

- Number of pairs of words/digits is equal to the number of steps.
- Identify the pattern in the input rearrangement. Then number the elements going left in their pattern order with 1L, 2L, 3L and so on. And number the elements going right in their pattern order with 1R, 2R,3R and so on.
- There is no auto filling, so there is no need to check step by step. The numbering can be done in one go.

STEP V is the last step of the input.

**Q.**Which is the 5th letter from right side in step V of the following input?

**Input:**

**87 when show 14 35 new beat ink 51 28**

**Label:**5L 5R 4R 1L 3L 3R 1R 2R 4L 2L

**Solution:**In the given illustration, the words/digits being arranged in the following manner: in the first step, lowest digit and lowest word in dictionary are placed at left most and right most side respectively, of the string and all other entities are placed as it is. Then in the 2nd step, next lowest digit and word are arranged to the left and right of the previously arranged digit and word simultaneously and so on. Therefore, arrangement is from left to left + right to right.

Here L1, L2 so on are used to represent left side and R1, R2 so on to represent right side.

Hence step 5 of the input is

Step 5: 87 51 35 28 14 beat ink new show when

So 5th from the right side is

__‘beat’__

__NOTE__**:**In this case 5th from right is not R5, but R1. So be careful while answering this type of question. Count backwards from the highest number label of that step in such cases.

**In mixed form i.e. both case 1 and 2 are used in one input then both the rules are used for each side**

__Case 4:__**If pairing of words and digits/words and words/ digits and digits is observed i.e. both are placed simultaneously in each step and in case if one is auto filled & other is not then no step is skipped.**

__NOTE:__
Its a blessing to have these Time saving short Tricks for Input Output in Reasoning just when the exam is just few days away. Share this knowledge with your fellow mates and let them also benefit from the same.

Also read:

Article by : Rajendra Rathore- Jodhpur

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