Number System-Railway Maths Part VI

Total Questions: 50

41. A boy was asked to multiply a given number with 5/11, instead, he divided the same number by 5/11. Thus, his answer exceeded the correct answer by 192. What is the given number? [RRB NTPC 11/02/2021 (Morning)]

Correct Answer: (d) 110
Solution:

42. Find the correct expression. [RRB NTPC 11/02/2021 (Evening)]

Correct Answer: (a) 541/99
Solution:

43. How many numbers between 500 and 700 are divisible by 11? [RRB NTPC 11/02/2021 (Evening)]

Correct Answer: (b) 18
Solution:

Total number between 500 and 700 = 200
Number divisible by 11 = 200/11
= 18 (quotient)

44. The tenth term of the sequence 2, 5, 8, 11,..... Will be: [RRB NTPC 11/02/2021 (Evening)]

Correct Answer: (b) 29
Solution:

For the given AP
First term a = 2 Common difference = d = 5 - 2 = 3
Tenth term = a + 9d , = 2 + 9 × 3 = 29

45. The sum of squares of the first ten natural numbers is: [RRB NTPC 11/02/2021 (Evening)]

Correct Answer: (c) 385
Solution:

Sum of squares of first ten natural numbers =(10(10 + 1)(20 + 1))/6
(10 × 11 × 21)/6 = 385 

46. Solve the following. 1-1+1-1+1-1+.......... (101 times)= ? [RRB NTPC 12/02/2021 (Morning)]

Correct Answer: (a) 1
Solution:

In the given sequence Sum of the Two conjugative number = 0
={1 - 1 + 1 - 1 + 1 - 1 +... ... ... 100ᵗʰ term} + 101ᵗʰ term, = 0 + 1, = 1

47. The product of first five whole numbers is: [RRB NTPC 12/02/2021 (Morning)]

Correct Answer: (b) 0
Solution:

First 5 whole number = 0, 1, 2, 3, 4
The product of first five whole numbers = 0

48. What fraction of 1275 is 816? [RRB NTPC 12/02/2021 (Morning)]

Correct Answer: (c) 16/25
Solution:

fraction of 1275 is 816
⇒ 816/1275 = 16/25

49. 42 × (4 + 2) =(42 × 4)+(42 × 2) is an example of: [RRB NTPC 12/02/2021 (Morning)]

Correct Answer: (b) distributive property
Solution:

42 × (4 + 2) =(42 × 4) + (42 × 2) is an example of distributive property.

50. Select the option. [RRB NTPC 15/02/2021 (Morning)]

Correct Answer: (b) 51/90
Solution: