The Average Age Of 10 Members Of A Committee Is The Same As It Was 4

1.	The Average Age Of 10 Members Of A Committee Is The Same As It Was 4 Years Ago, Because An Old Member Has Been Replaced By A Young Member.find How Much Younger Is The New Member ?
Answer» LET the members be Old Having AGE O + other 9 having ages x and New one having age Y Sum of their ages = (Y + 9 × x) and average = (Y + 9 × x)/10 Before 4 years sum was (O + 9 x – 10 × 4) and average = (O + 9 x – 10 × 4) /10 EQUATING, Y + 9 x = O + 9x – 40 Y = O – 40 Younger is 40 years younger than Old one. Let the members be Old Having age O + other 9 having ages x and New one having age Y Sum of their ages = (Y + 9 × x) and average = (Y + 9 × x)/10 Before 4 years sum was (O + 9 x – 10 × 4) and average = (O + 9 x – 10 × 4) /10 equating, Y + 9 x = O + 9x – 40 Y = O – 40 Younger is 40 years younger than Old one.

The Average Age Of 10 Members Of A Committee Is The Same As It Was 4 Years Ago, Because An Old Member Has Been Replaced By A Young Member.find How Much Younger Is The New Member ?

Answer»

LET the members be Old Having AGE O + other 9 having ages x and New one having age Y

Sum of their ages = (Y + 9 × x) and average = (Y + 9 × x)/10

Before 4 years sum was (O + 9 x – 10 × 4) and average = (O + 9 x – 10 × 4) /10

EQUATING, Y + 9 x = O + 9x – 40

Y = O – 40

Younger is 40 years younger than Old one.

Let the members be Old Having age O + other 9 having ages x and New one having age Y

Sum of their ages = (Y + 9 × x) and average = (Y + 9 × x)/10

Before 4 years sum was (O + 9 x – 10 × 4) and average = (O + 9 x – 10 × 4) /10

equating, Y + 9 x = O + 9x – 40

Y = O – 40

Younger is 40 years younger than Old one.