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

    Question

    C is 50% more efficient than D. Together, they can

    finish a task in 12 days. How many days will D alone take to complete the task?
    A 36 days Correct Answer Incorrect Answer
    B 30 days Correct Answer Incorrect Answer
    C 40 days Correct Answer Incorrect Answer
    D 42 days Correct Answer Incorrect Answer

    Solution

    Let D’s efficiency be x. Then, C’s efficiency is 1.5x. Together, their combined efficiency is x + 1.5x = 2.5x. Now, total work = 2.5x × 12 = 30x. D’s time to complete the work alone = total work ÷ D's efficiency = 30x ÷ x = 30 days. Final Answer: (b) 30 days

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