Arithmetic Reasoning – Railway Reasoning

Total Questions: 52

1. If 3 is added to each odd digit and 1 is subtracted from each even digit in the number 42514563, what will be the difference between the highest and lowest digits thus formed? [Group - D 17/08/2022 (Morning)]

Correct Answer: (b) 7
Solution:

42514563
If 3 is added to each odd digit and 1 is subtracted from each even digit then Number = 31843856
Difference between largest and smallest = 8 - 1 = 7

2. This question is based on the following 3-digit numbers. [Group - D 18/08/2022 (Evening)]

543 769 552 342 245
(Example - 697 - First digit = 6, second digit = 9 and third digit = 7)
If 1 is added to the first digit of every number, in how many numbers will the first digit be exactly divisible by the third digit of the same number?

Correct Answer: (d) Three
Solution:

Given statement:
543 769 552 342 245
On adding 1 to every first digit, we get 643 869 652 442 345
Here, 643 (as 6 is divisible by 3), 652 (as 6 is divisible by 2), 442 (as 4 is divisible by 2)
Therefore, there are 3 such numbers.

3. The following question is based on the given seven, three-digit numbers. [Group - D 23/08/2022 (Evening)]

(left)347,486,627,113,721,418, 779 (right)
(For example, in the number 456: 6 = units digit, 5 = tens digit and 4 = hundreds digit)
Note - All operations will be done from left to right. If 2 is added to the hundreds digit of each of the above numbers, then in how many of the numbers thus obtained, the hundreds digit will be exactly divisible by the tens digit?

Correct Answer: (a) 3
Solution:

Given numbers:
(left) 347,486, 627,113,721, 418, 779 (right) After adding 2 to hundred’s digit of each number, we get:
(left) 547, 686, 827, 313, 921, 618, 979 (right)
We can see that there are 3 numbers (827, 313, 618) in which hundreds digit is divisible by tens digit.

4. Study the following number arrangement and answer the question given below. All numbers given below are 2 digit numbers. [Group - D 01/09/2022 (Afternoon)]

13 56 46 23 16 34 25 19 78 85 86 24 29 73 94 52 64 63
What will be the difference between the sum of the first half and second half of the above series?

Correct Answer: (d) 260
Solution:

According to the question sum of first half and second half
13 + 56 + 46 + 23 + 16 + 34 + 25 + 19 + 78 = 310
85 + 86 + 24 + 29 + 73 + 94 + 52 + 64 + 63 = 570
Difference between first half and second half = 570 - 310 = 260

5. If 5 is added to each of the following numbers, and then the digits of each number are written in reverse order, and the numbers so obtained are arranged in ascending order, then the position of how many numbers will remain unchanged? [Group - D 06/09/2022 (Morning)]

224, 637, 816, 471, 303

Correct Answer: (a) one
Solution:

Given : 224, 637, 816, 471, 303 If 5 added to each number then we get, 229, 642, 821, 476, 308
Now if we write the digits of each number in reverse order, we get following arrangement:
922, 246, 128, 674, 803 Now if we arrange all the numbers in ascending order then, 128, 246, 674, 803, 922
So we can clearly see that 246 is the only number whose position remains same.

6. This question is based on the five, three digit numbers given below. [Group - D 15/09/2022 (Morning)]

(Left) 986 432 631 387 267 (Right) (Example - 123 - First digit = 1, second digit = 2 and third digit = 3)
NOTE - All operations to be done from left to right.
What will be the resultant if the second digit of the third greatest number is added to the third digit of the smallest number?

Correct Answer: (b) 10
Solution:

Given three digit number:
(left) 986 432 631 387 267 (right) 3rd greatest number = 432 , smallest number = 267
2nd digit of 3rd greatest number + 3rd digit of smallest number = 3 + 7 = 10

7. This question is based on the five, three-digit numbers given below. [Group - D 18/09/2022 (Evening)]

465 638 359 987 563
If the positions of the first two digits in each number are reversed, then the difference between the first digit of the greatest number and the first digit of the lowest number is equal to: (Example - 697 - First digit = 6, second digit = 9 and third digit = 7)

Correct Answer: (d) 5
Solution:

465 638 359 987 563
As per the instructions, 645 368 539 897 653
Now, first digit of the greatest number = 8 97 = 8
First digit of the lowest number = 3 Required difference = 8 - 3 = 5

8. This question is based on the five, five-digit numbers given below. [Group - D 27/09/2022 (Evening)]

(Left) 72238 83745 52227 72253 63776 (Right)
(Example: 697 – first digit = 6, second digit = 9, third digit = 7)
(NOTE: All operations to be done from left to right)
If 1 is subtracted from the first digit of every number, in how many numbers will the first digit be exactly divisible by 3?

Correct Answer: (d) Two
Solution:

(Left)72238 83745 52227 72253 63776 (Right)
As per the instruction,
(Left) 62238 73745 42227 62253 53776 (Right)
Here, 62238 and 62253 are divisible by 3, so there are only two numbers whose first digit is divisible by 3.

9. Please read the following information carefully and answer the questions that follows. [NTPC CBT - I 06/04/2021 (Evening)]

Richa, Rohini, Roli, Roshan and Rita are five friends. Each one of them has eight balls. Rohini gives three balls to Roshan, who gives five balls to Richa. Richa gives four balls to Roli, who in turn gives three balls to Rita. Rita gives two balls each to Roshan and Rohini. After the final distribution, how many balls are there in total with all five friends?

Correct Answer: (d) 40
Solution:

Number of balls before and after distribution remains the same.
Number of total balls = 5 × 8 = 40

10. If 2 is added to each odd digit of the number 34135278, and 1 is subtracted from each even digit, then what will be the sum of the third digits from the left and the third from the right? [Group - D 17/08/2022 (Afternoon)]

Correct Answer: (d) 4
Solution:

Given number = 34135278 After adding 2 to each odd digit and subtracting 1 from each even digit,
the resultant number = 53357197
The sum of third digit from the left and third digit from the right = 3 + 1 = 4