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The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member. Find how much younger is the new member ? |
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Answer» Let the sum of nine member (total) =xand the age of old one=zso its average 4 yrs before=(x+z)/10.after 4 yrs let z be replaced by y.so now avg=(x+4*10+y)/10 now (x+z)/10=(x+40+y)/10so after solving it foundz=y+40.so old person is 40yrs older than young one. |
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