Question

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.

Q: Answer-There are 7 people in a group. Average age of the group decreases by 5 when two more people join the...

From statement I People becomes 9 from 7, and average decreases by 5. Let lsquonrsquo is previous average and then lsquon - 5rsquo is new average. So Sum of ages of 2 new people becomes 9 times n ndash 5 ndash 7 times n which is given 25 So 9 times n ndash 5 ndash 7 times n 25 So 9n ndash 45 ndash 7n 25 or 2n 2545 70 So, n 702 35 So average of new group 35 ndash 5 30 From statement II Total age of 7 people is 245 years, so their average 2457 35 So, average of new group 35 ndash 5 30 So answer can be determined by either of statement I or II.

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.

A If the data in statement I alone is sufficient to answer the question.

B If the data in statement II alone is sufficient to answer the question.

C If the data either in statement I alone or statement II alone are sufficient to answer the question.

D If the data given in both I and II together are not sufficient to answer the question.

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