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

    Question

    The average wage of a group of 20 labourers is Rs. 420.

    If 4 persons receiving average wage of Rs. 300 leave the group and 2 persons receiving average wage of Rs. K join the group, then the average wage of the group increases by Rs. 50. Find the value of ‘K’.
    A 630 Correct Answer Incorrect Answer
    B 620 Correct Answer Incorrect Answer
    C 660 Correct Answer Incorrect Answer
    D 680 Correct Answer Incorrect Answer

    Solution

    Total wage of 20 labourers in the initial group = 20 × 420 = Rs. 8400 New average wage of the group = 420 + 50 = Rs. 470 New number of labourers in the group = 20 – 4 + 2 = 18 So, according to the question, 8400 – 4 × 300 + 2K = 470 × 18 Or, 8400 – 1200 + 2K = 8460 Or, 7200 + 2K = 8460 Or, 2K = 8460 – 7200 = 1260 Or, K = (1260/2) = 630

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