Selected MCQ

Current Question
A number is decreased by 10% and then by another 10%. Total decrease is ____.
  • A. 20%
  • B. 19%
  • C. 18%
  • D. 21%
Correct Answer: B
Explanation:
0.9 × 0.9 = 0.81 → 19% decrease.
Related Question 1
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 2
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 3
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 4
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 5
If a number increases by 20% and then by another 30%, total increase is ____.
  • A. 50%
  • B. 56%
  • C. 60%
  • D. 65%
Correct Answer: B
Explanation:
1.2 × 1.3 = 1.56 → 56%.