New Enroll in RBI Grade B New Batch - Starts on May 21

    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?
    A 124 mins Correct Answer Incorrect Answer
    B 116 mins Correct Answer Incorrect Answer
    C 128 mins Correct Answer Incorrect Answer
    D 120 mins Correct Answer Incorrect Answer

    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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