Selected MCQ

Current Question
If a number is decreased by 10% and then by 20%, net decrease is ____.
  • A. 28%
  • B. 30%
  • C. 32%
  • D. 25%
Correct Answer: A
Explanation:
0.9 × 0.8 = 0.72 → 28% decrease.
Related Question 1
If a number is decreased by 25% and becomes 150, the original number is ____.
  • A. 200
  • B. 180
  • C. 220
  • D. 240
Correct Answer: A
Explanation:
x × 0.75 = 150 → x = 200.
Related Question 2
A number when decreased by 20% becomes 80. The number is ____.
  • A. 90
  • B. 100
  • C. 120
  • D. 110
Correct Answer: B
Explanation:
x × 0.8 = 80 → x = 100.
Related Question 3
If a number is decreased by 20% and becomes 80, original number ____.
  • A. 90
  • B. 95
  • C. 100
  • D. 110
Correct Answer: C
Explanation:
0.8x = 80.
Related Question 4
If a number is decreased by 30% and then increased by 30%, net effect is ____.
  • A. No change
  • B. 9% decrease
  • C. 9% increase
  • D. 6% decrease
Correct Answer: B
Explanation:
0.7 × 1.3 = 0.91 → 9% decrease.
Related Question 5
A number is increased by 40% and then decreased by 20%. Net increase is ____.
  • A. 10%
  • B. 12%
  • C. 15%
  • D. 20%
Correct Answer: B
Explanation:
1.4 × 0.8 = 1.12 → 12%.