SOLVED PAPER 2021 (CDS) (I) (Elementary Mathematics)

Total Questions: 100

1. If the number 413283P759387 is divisible by 13, then what is the value of P ?

Correct Answer: (d) 8
Solution:


2. What is the remainder when 2¹⁰⁰⁰⁰⁰⁰ is divided by 7?

Correct Answer: (b) 2
Solution:


3. Solve it ?

Correct Answer: (a) Zero
Solution:Given set,

4. Consider the pairs of prime numbers (m, n)between 50 and 100 such that m - n = 6. How many such pairs are there?

Correct Answer: (d) 5
Solution:Given,

5. How many terms are there in the following product?

Correct Answer: (d) 60
Solution:Given product,

6. What is the remainder when 27²⁷ - 15²⁷ is divided by 6 ?

Correct Answer: (a) 0
Solution:


7. If a + b + c = 0, then which of the following are correct?

1. a³ + b³ +  c³  = 3abc
2. a² + b² +  c²  = 2(ab + bc + ca)
3. a³ + b³ +  c³  = 3ab(a + b)

Select the correct answer using the code given below.

Correct Answer: (d) 1, 2 and 3
Solution:



8. Solve it ?

Correct Answer: (b) 1
Solution:Given,



9. What is the unit digit in the expansion of 67³² ?

Correct Answer: (a) 1
Solution:Given term is 67³².

10. Solve it ?

Correct Answer: (c)
Solution: