15. Practice Question Set A — Basic Level

A1. (Prime Numbers) Which of the following is a prime number? (a) 91 (b) 97 (c) 111 (d) 121

A2. (Place Value) Find the place value of 6 in the number 46,281. (a) 6 (b) 60 (c) 600 (d) 6000

A3. (Number Series / Sum Formula) Find the sum of the first 20 natural numbers. (a) 190 (b) 200 (c) 210 (d) 220

A4. (Co-prime Numbers) Which of the following pairs is co-prime? (a) 15, 20 (b) 8, 9 (c) 12, 18 (d) 14, 21

A5. (Unit Digit — Cyclicity) Find the unit digit of 7^45. (a) 7 (b) 9 (c) 3 (d) 1

A6. (HCF) Find the HCF of 12 and 18. (a) 3 (b) 6 (c) 9 (d) 36

A7. (LCM) Find the LCM of 4 and 6. (a) 8 (b) 10 (c) 12 (d) 24

A8. (Divisibility by 11) Which of the following numbers is divisible by 11? (a) 4567 (b) 5148 (c) 6789 (d) 8912

A9. (Number of Factors) Find the number of factors of 36. (a) 6 (b) 8 (c) 9 (d) 12

A10. (HCF–LCM Relation) The HCF of two numbers is 4 and their LCM is 48. If one number is 16, find the other. (a) 8 (b) 10 (c) 12 (d) 16

A11. (Irrational Numbers) Which of the following is an irrational number? (a) √16 (b) √25 (c) √7 (d) 0.333…

A12. (Remainders) Find the remainder when 29 is divided by 6. (a) 1 (b) 3 (c) 5 (d) 2

A13. (Divisibility by 12) Which of the following numbers is divisible by 12? (a) 144 (b) 128 (c) 162 (d) 134

A14. (Prime Numbers) The smallest prime number is: (a) 0 (b) 1 (c) 2 (d) 3

A15. (Laws of Indices) Simplify: 2⁵ × 2³ ÷ 2⁴ (a) 8 (b) 16 (c) 32 (d) 64

A16. (Base Conversion) Convert (101)₂ to decimal. (a) 3 (b) 4 (c) 5 (d) 6

A17. (Surds) Simplify √98. (a) 7√2 (b) 2√7 (c) 14√2 (d) 7√7

A18. (Divisibility by 9) Which of the following numbers is divisible by 9? (a) 4562 (b) 6531 (c) 7245 (d) 8321

A19. (Number Series) Find the next term: 2, 6, 12, 20, 30, ? (a) 36 (b) 40 (c) 42 (d) 45

A20. (Number of Factors) How many factors does 100 have? (a) 6 (b) 8 (c) 9 (d) 12