Question

The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member.

Answer 1

HY FRIEND  HERE IS YOUR ANSWER ⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛  ✔Let the sum of nine member (total)=x  ✔ the age of old one = z   ⭐ FIRST STEP IS     ............................ ⏭ its average 4 yrs before=(x+z)/10.  ⏭ after 4 yrs let z be replaced by y.  ⭐ SECOND STEP IS .................................... ⏭ now avg=(x+4*10+y)/10  ⏭ (x+z)/10=(x+40+y)/10  so after solving it found         z=y+40.  ✔so old person is 40yrs ✔older than young one .................................................................. THANKYOU BRAINLY USER BE BRAINLY