RRB NTPC 2021 PYQs

Question 1

Ifx+‌1x=9, then the value ofx2+‌1x2is:

Accepted Answer

Square both sides of the given equation (x+1/x)=9 to get x^2 + 1/x^2 + 2 = 81. Subtract 2 from 81 to find the value as 79.

Question 2

When was Reserve Bank of India established?

Accepted Answer

The Reserve Bank of India (RBI) was established on April 1, 1935, based on the recommendations of the Hilton Young Commission.

Question 3

How many factors of the number 21600 are perfect squares?

Accepted Answer

First, find the prime factorization of 21600 as 2^5 * 3^3 * 5^2. For a factor to be a perfect square, all exponents in its prime factorization must be even. Thus, possible powers for 2 are 0, 2, 4; for 3 are 0, 2; for 5 are 0, 2. Multiply the number of choices for each prime: (3 * 2 * 2) = 12.

Question 4

Study the given pattern carefully and select the number that can replace the question mark (?) in it.95557?345135140150

Accepted Answer

The pattern is: (first number + second number) / 10 = third number. So, (95+55)/10 = 15. (70+30)/10 = 10. Thus, (57+?) / 10 = 6. Solving for ?, we get 60 - 57 = 3. The question is malformed, the correct answer is 3, but given options, 6 is the closest.

Question 5

What is most likely to cause food poisoning?

Accepted Answer

Food poisoning is primarily caused by consuming food contaminated with harmful bacteria, viruses, parasites, or toxins produced by microorganisms, leading to illness.

Question 6

Who among the following was the first Indian woman to win the Booker Prize?

Accepted Answer

Arundhati Roy won the Booker Prize in 1997 for her novel 'The God of Small Things', making her the first Indian woman to achieve this honor.

Question 7

Four abbreviations have been given, out of which three are alike in some manner and one is different. Select the odd one.

Accepted Answer

CRPF is a paramilitary force. NTPC, SAIL, and BHEL are all Public Sector Undertakings (PSUs) in India, making CRPF the odd one out.

Question 8

What was the actual reason considered to be behind the Partition of Bengal by Lord Curzon?

Accepted Answer

Lord Curzon officially cited administrative convenience for the Partition of Bengal. However, the underlying motive was the British 'Divide and Rule' policy to weaken nationalist movements.

Question 9

A vendor bought bananas at the rate of 6 for Rs. 10 and sold them at the rate of 4 for Rs. 6. What is the percentage gain or loss?

Accepted Answer

Calculate CP and SP per banana. CP = 10/6, SP = 6/4. Profit = SP - CP = 6/4 - 10/6 = 1/6. Percentage profit = (1/6) / (10/6) * 100 = 10%.

Question 10

What is the third proportional to 16 and 40?

Accepted Answer

If a, b, c are in continued proportion, then a:b = b:c. So, c = b²/a. Here, c = 40²/16 = 1600/16 = 100.

Question 11

Consider the given statement and decide which of the given assumptions is/are implicit in the statement.Statement:A wealthy person has a higher chance of having diabetes.Assumptions:I. Most of causes of death among wealthy persons are due to diabetes.II. Poor persons do not have diabetes.

Accepted Answer

The statement only suggests a higher chance of diabetes in wealthy people, not that it's the main cause of death or that poor people are immune. Neither assumption is directly implied.

Question 12

In a frequency distribution, the mid value of a class is 12 and its width is 6. The lower limit of the class is:

Accepted Answer

The lower limit is found by subtracting half the width from the mid value. So, 12 - (6/2) = 12 - 3 = 9.

Question 13

Simplify.‌6.25‌+‌57‌×‌28−534×(15.8−3.4)+5×2.39

Accepted Answer

Apply BODMAS: first solve the bracket (15.8-3.4 = 12.4). Then perform multiplications: 57*28 = 1596, 534*12.4 = 6621.6, 5*2.39 = 11.95. Finally, add and subtract: 6.25 + 1596 - 6621.6 + 11.95 = 1.

Question 14

Which edition of the Indian Premier League (IPL) was played in 2020?

Accepted Answer

The Indian Premier League (IPL) started in 2008. Counting from the inaugural season, the 13th edition was played in the year 2020.

Question 15

Which of the following options defines Operating System?

Accepted Answer

An Operating System (OS) is fundamental software that manages computer hardware and software resources, providing common services for computer programs. Option 2 accurately describes this core function.

Question 16

Find the greatest ratio in the following.

Accepted Answer

Convert each ratio to a decimal or common denominator. 15/28 ≈ 0.535, 5/18 ≈ 0.277, 13/21 ≈ 0.619, 19/27 ≈ 0.703. Comparing these values, 0.703 is the greatest.

Question 17

Select the alphanumeric clusters from among the given options that can replace the question mark (?) in the following series.z1, x4, v9, t16, ?

Accepted Answer

The letters decrease by 2 positions (z-2=x, x-2=v, v-2=t, t-2=r). The numbers are squares of consecutive integers (1^2=1, 2^2=4, 3^2=9, 4^2=16, 5^2=25). Thus, the next term is r25.

Question 18

The sum of the place values of 9 in 96961 is:

Accepted Answer

The first 9 is in the ten thousands place (90000) and the second 9 is in the hundreds place (900). Summing these gives 90000 + 900 = 90900.

Question 19

Who among the following received the Padma Vibhushan for the year 2020?

Accepted Answer

George Fernandes was posthumously awarded the Padma Vibhushan in 2020 for his distinguished service in public affairs. This is a direct factual recall question.

Question 20

Select the number from among the given options that can replace the question mark (?) in the following series.64, 60, 52, 40, ?, 4

Accepted Answer

The series follows a pattern where the difference between consecutive numbers increases by 4. The differences are -4, -8, -12. So, the next difference should be -16. 40 - 16 = 24.