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

    Question

    In each of the following questions, a question is followed by two statement. Read all the statements and find that which statements are required to answer the question and answer accordingly.

    There are 7 people in a group. Average age of the group

    decreases by 5 when two more people join the group. Find the average age of the new group. Statement I: Sum of the ages of the two people who joined later is 25 yrs. Statement II: Total of the ages of people originally was 245 yrs.
    A If the data in statement I alone is sufficient to answer the question. Correct Answer Incorrect Answer
    B If the data in statement II alone is sufficient to answer the question. Correct Answer Incorrect Answer
    C If the data either in statement I alone or statement II alone are sufficient to answer the question. Correct Answer Incorrect Answer
    D If the data given in both I and II together are not sufficient to answer the question. Correct Answer Incorrect Answer
    E If the data in both the statements I and II together are necessary to answer the question. Correct Answer Incorrect Answer

    Solution

    From statement I: People becomes 9 from 7, and average decreases by 5. Let ‘n’ is previous average and then ‘n - 5’ is new average. So Sum of ages of 2 new people becomes 9 × (n – 5) – 7 × n which is given 25 So 9 × (n – 5) – 7 × n = 25 So 9n – 45 – 7n = 25 or 2n = 25+45= 70 So, n = 70/2 = 35 So average of new group = 35 – 5 = 30 From statement II: Total age of 7 people is 245 years, so their average = 245/7 = 35 So, average of new group = 35 – 5 = 30 So answer can be determined by either of statement I or II.

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