RRB NTPC 2021 PYQs

Question 1

The value of a machine depreciates at the rate of 10% per annum. If its present value is Rs. 1,62,000, what was the value (in Rs.) of the machine 2 years ago?

Accepted Answer

Let the value 2 years ago be P. Present value = P * (1 - 0.10)^2. So, 162000 = P * (0.9)^2 = P * 0.81. Thus, P = 162000 / 0.81 = 200000.

Question 2

Which type of storage device is a Hard Disc?

Accepted Answer

Hard disks are non-volatile storage devices used for long-term data storage, making them a classic example of secondary storage.

Question 3

Given below are few statements and their respective codes in a particular language:Horse are Cat – XYTCat is Blue – TMZBlue is Cloud – ZMSWhich of the given options will be the code for the following statement in that language:Blue Cat is Cloud-?

Accepted Answer

By comparing the given statements, 'Cat' is common in the first two, so its code is 'T'. 'Blue' is common in the last two, so its code is 'Z'. 'is' is common in the second and third, so its code is 'M'. 'Cloud' is 'S'. Thus, Blue Cat is Cloud is ZTMS.

Question 4

How many world heritage sites have been protected by UNESCO as of June 2020?

Accepted Answer

As of June 2020, UNESCO had designated 1121 World Heritage Sites globally. This is a direct factual recall question.

Question 5

If the denominator of a rational number is of the form 2n5m, where n and m are non-negative integers, then what will be the  decimal expansion of the number?

Accepted Answer

A rational number has a terminating decimal expansion if and only if its denominator, in simplest form, has prime factors only 2 and 5.

Question 6

Name the Kalvari class submarine launched in Mumbai in Nov 2020.

Accepted Answer

INS Vagir, the fifth submarine of the Kalvari class, was launched in November 2020 at Mazagon Dock Shipbuilders in Mumbai. This is a direct factual recall question.

Question 7

A, B and C entered into partnership. A invested 3 times as much as B and B invested‌23times of what C invested. At the end of the year the total profit was Rs.6,600. B's share in the profit is:

Accepted Answer

Establish the investment ratio A:B:C as 6:2:3. The total ratio sum is 11. B's share is (2/11) * 6600, which equals Rs. 1200.

Question 8

A shopkeeper gives 20% discount on MRP. Joginder buys a suitcase from the shop, at an additional discount of 20% on the reduced price. If the MRP of the suitcase is Rs. 1,200, then find the purchasing price paid by Joginder.

Accepted Answer

First discount: 20% of 1200 = 240. Price after first discount = 1200 - 240 = 960. Second discount: 20% of 960 = 192. Final price = 960 - 192 = 768.

Question 9

An observer 1.5 m tall is standing 28.5 m away at the same level as the foot of a tower. If angle of elevation of the observer watching the top of the tower is 45 degrees then what is the height of the tower?

Accepted Answer

The horizontal distance is 28.5m. With an elevation angle of 45 degrees, the height above the observer's eye level is 28.5m (tan 45 = 1). Add the observer's height (1.5m) to get the total tower height: 28.5 + 1.5 = 30m.

Question 10

Which famous person identified with the slogan- "Do or Die"?

Accepted Answer

Mahatma Gandhi gave the 'Do or Die' call during the Quit India Movement in 1942, urging Indians to achieve independence or die trying.

Question 11

What is the full form of CLI in Computer terminology?

Accepted Answer

CLI stands for Command Line Interface. It is a text-based interface used for interacting with a computer program or operating system.

Question 12

(√7+√9)(√7−√9)is equal to:

Accepted Answer

This is in the form (a+b)(a-b) = a² - b². Here a=√7 and b=√9. So, (√7)² - (√9)² = 7 - 9 = -2.

Question 13

Who is considered the father of white revolution in India?

Accepted Answer

Verghese Kurien is widely recognized as the 'Father of the White Revolution' in India for his pivotal role in establishing the dairy cooperative movement, Operation Flood.

Question 14

Select the number from among the given options that can replace the quesion mark? in the following series.7, 12,19, ?, 39

Accepted Answer

The series follows a pattern where the difference between consecutive numbers increases by 2. The differences are +5, +7, so the next difference should be +9. Thus, 19 + 9 = 28.

Question 15

What is the full form of COBOL?

Accepted Answer

COBOL stands for Common Business Oriented Language. It is a high-level programming language primarily used for business applications.

Question 16

___________ was celebrated as the First War of Indian Independence.

Accepted Answer

The Uprising of 1857 is widely recognized and celebrated as the First War of Indian Independence, a pivotal event in India's struggle for freedom.

Question 17

Which of the following includes genetic engineering?

Accepted Answer

Genetic engineering is directly related to manipulating genes. Therefore, 'Gene revolution' is the most appropriate term that includes genetic engineering.

Question 18

The persistence of sound in an auditorium is the result of repeated reflections of sound and is called _______.

Accepted Answer

The persistence of sound due to multiple reflections in an enclosed space like an auditorium is specifically defined as reverberation. It's a direct physics concept.

Question 19

Pointing to Sohan, Rahul said "Sohan is the husband of my wife's daughter". How is Sohan related to Rahul?

Accepted Answer

Rahul's wife's daughter is Rahul's daughter. Sohan is the husband of Rahul's daughter. Therefore, Sohan is Rahul's son-in-law.

Question 20

Which one of the following is called a super-network or meta-network?

Accepted Answer

The Internet is a global network of interconnected computer networks, often referred to as a 'super-network' or 'meta-network' due to its vast scale and encompassing nature.