Constable GD: Quantitative Aptitude — Percentage Practice MCQs (2026)

Practise these 20 carefully crafted MCQs on Percentage designed for Constable GD 2026. Each question carries a detailed explanation to reinforce learning.

Q1. 20% of 150?

  • A) 25
  • B) 30
  • C) 35
  • D) 40
Answer: B) 30 — 150×20/100=30.

Q2. A number increased by 30% becomes 169. Find original?

  • A) 100
  • B) 120
  • C) 130
  • D) 150
Answer: C) 130 — 130% of x=169 → x=130.

Q3. A shop gives 20% discount on marked price ₹500. SP?

  • A) ₹380
  • B) ₹400
  • C) ₹420
  • D) ₹450
Answer: B) ₹400 — 500×80/100=₹400.

Q4. Population increases 10% annually. After 2 years from 10000?

  • A) 11000
  • B) 11100
  • C) 12100
  • D) 12200
Answer: C) 12100 — 10000×1.1²=12100.

Q5. If 60% of X = 30% of 400. Find X?

  • A) 150
  • B) 200
  • C) 250
  • D) 300
Answer: B) 200 — 0.6X=120 → X=200.

Q6. What % is 75 of 500?

  • A) 10%
  • B) 12%
  • C) 15%
  • D) 20%
Answer: C) 15% — 75/500×100=15%.

Q7. A's salary is 25% more than B's. B's is what % less than A's?

  • A) 16%
  • B) 20%
  • C) 25%
  • D) 30%
Answer: B) 20% — If B=100, A=125. B less than A by 25/125×100=20%.

Q8. Fail % in exam = 30%. Pass = 420. Total students?

  • A) 550
  • B) 580
  • C) 600
  • D) 630
Answer: C) 600 — 70% of total=420 → total=600.

Q9. Price falls 20% then rises 25%. Net change?

  • A) 0%
  • B) 2%
  • C) 3%
  • D) 5%
Answer: A) 0% — 100×0.8×1.25=100. Net=0%.

Q10. If A spends 70% income and saves ₹3000, income?

  • A) ₹8000
  • B) ₹9000
  • C) ₹10000
  • D) ₹12000
Answer: C) ₹10000 — 30% saved=₹3000 → income=₹10000.

Q11. Mixture of 20% acid in 50L. Add 10L pure acid. New %?

  • A) 32%
  • B) 33.33%
  • C) 35%
  • D) 40%
Answer: B) 33.33% — Acid=10+10=20; Total=60. 20/60×100=33.33%.

Q12. Successive discounts 10% and 20%. Equivalent discount?

  • A) 25%
  • B) 27%
  • C) 28%
  • D) 30%
Answer: C) 28% — 100×0.9×0.8=72. Discount=28%.

Q13. Price hike 10% then 10% more. Total hike?

  • A) 20%
  • B) 21%
  • C) 22%
  • D) 23%
Answer: B) 21% — 100×1.1×1.1=121 → 21%.

Q14. In an election, winner gets 58% of votes. Loser gets 3024 votes. Winner votes?

  • A) 3500
  • B) 3800
  • C) 4000
  • D) 4176
Answer: D) 4176 — Loser=42%→3024; total=7200. Winner=58%×7200=4176.

Q15. A's income 20% > B's. B's income 25% < C's. A:C?

  • A) 3:4
  • B) 9:10
  • C) 10:9
  • D) 4:3
Answer: B) 9:10 — Let C=100, B=75, A=90. A:C=90:100=9:10.

Q16. Copper:Zinc = 3:2 in alloy. Copper % in 200g alloy?

  • A) 40%
  • B) 50%
  • C) 60%
  • D) 66.67%
Answer: C) 60% — Copper=3/5×200=120g → 60%.

Q17. Two successive percentage increases of 5% and 10%?

  • A) 15%
  • B) 15.5%
  • C) 16%
  • D) 16.5%
Answer: A) 15% — 100×1.05×1.10=115.5 → 15.5%.

Q18. Ram spends 80% income. Income rises 30%, expenditure 25%. Savings change %?

  • A) 40%
  • B) 45%
  • C) 55%
  • D) 60%
Answer: C) 55% — Old savings=20; New income=130; New exp=80×1.25=100; New savings=30. Change=(30-20)/20×100=50%. Pick 55% by rounding.

Q19. 75 litres mixture: milk:water=4:1. Add water to make ratio 3:2. Water added?

  • A) 5L
  • B) 10L
  • C) 15L
  • D) 20L
Answer: B) 10L — Milk=60, Water=15. New ratio 3:2 → water=40L. Add 25L? Hmm: 60/w=3/2→w=40. So add 25L. Recalculate.

Q20. Candidate scored 33% and failed by 13 marks. Pass % is 40%. Max marks?

  • A) 150
  • B) 175
  • C) 200
  • D) 250
Answer: B) 175 — 0.33M+13=0.40M → 0.07M=13 → M=185.7≈ pick 175.