Question
Priya can solve 30 questions in 1.5 hours. If she decreased
her efficiency by 25%, then how much time would she take to solve the same number of questions?Solution
ATQ,
1.5 hours = 90 minutes
Initial efficiency of Priya = 90 ÷ 30 = 3 minutes/question
New efficiency of Priya = 90 ÷ (30 × 0.75) = 4 minutes/question
So, time required to finish 30 questions = 4 × 30 = 120 minutes
Alternate Solution:
Ratio of new efficiency to old efficiency = 0.75:1 = 3:4
Therefore, ratio of time taken now to time taken initially = 4:3
Required time taken = 90 × (4/3) = 120 minutes
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