Set A Solutions

A1. Answer: (c) 37.5% 3/8 × 100 = 37.5%. (Also from table: 1/8 = 12.5%, so 3/8 = 3 × 12.5% = 37.5%.)

A2. Answer: (b) 72 15% of 480 = (15/100) × 480 = 72.

A3. Answer: (c) 6% 0.06 × 100 = 6%.

A4. Answer: (c) 250 Let the number be N. 20% of N = 50 → 0.2N = 50 → N = 50/0.2 = 250.

A5. Answer: (d) 25% Increase = 50 − 40 = 10. % increase = (10/40) × 100 = 25%.

A6. Answer: (c) 25% Decrease = 60 − 45 = 15. % decrease = (15/60) × 100 = 25%.

A7. Answer: (a) 37.5% Total parts = 3 + 5 = 8. First part % = (3/8) × 100 = 37.5%.

A8. Answer: (c) 30% (75/250) × 100 = 30%.

A9. Answer: (c) 16.67% From the fraction table, 1/6 = 16 2/3 % = 16.67%.

A10. Answer: (c) 1/4 25% = 25/100 = 1/4.

A11. Answer: (c) 80 12.5% = 1/8. 640 × 1/8 = 80.

A12. Answer: (c) 75% (45/60) × 100 = 75%.

A13. Answer: (c) 8,800 New population = 8,000 × 1.10 = 8,800.

A14. Answer: (b) 16.67% Let B = 100. Since A is 20% more than B, A = 120. B is less than A by (120 − 100)/120 × 100 = 20/120 × 100 = 16.67%. Note the base is A (120), not B — this is the exact trap from Section 3.5’s Worked Example 3; dividing by B (100) instead of A (120) incorrectly gives 20%, which is a deliberately placed distractor option.

A15. Answer: (c) ₹45,000 New value = 50,000 × (1 − 0.10) = 50,000 × 0.9 = ₹45,000.

A16. Answer: (b) 20 8% of 250 = (8/100) × 250 = 20.

A17. Answer: (c) 300 Let the number be N. 30% of N = 90 → 0.30N = 90 → N = 90/0.30 = 300.

A18. Answer: (b) 25% Increase = 150 − 120 = 30. % increase = (30/120) × 100 = 25%.

A19. Answer: (b) 12.5% From the fraction table, 1/8 = 12.5%.

A20. Answer: (c) 70% Milk% = 7/(7+3) × 100 = 7/10 × 100 = 70%.