Question

Aman used to solve 4 questions in 12 minutes. After much practice, he is now able to solve 8 questions in 16 minutes. What is the percentage decrease in the time he has achieved to solve each question?

Answer 1

Number of questions Aman used to solve initially = 4 questions in 12 minutes
Time needed to solve a question = $\frac{12}{4}$ = 3 minutes

Number of questions Aman can now solve after practising = 8 questions in 16 minutes
Time needed to solve a question = $\frac{16}{8}$ = 2 minutes

Decrease in time to solve a single question = 3 - 2 = 1 minute
Decrease % = $\frac{\text{Decrease in value}}{\text{Original value}}\times 100$
On substituting the values, we get:
Decrease % = $\frac{1}{3}\times 100$ = 33.33%