MODERATE The sum of ages of 5 members comprising a family, 3 years ago was 80. The average age of family ...

Devikanth Goud

Devikanth Goud

New Member
Can someone please solve this with a detailed explanation:

  • The sum of ages of 5 members comprising a family, 3 years ago was 80.
  • The average age of family today is the same as it was 3 years ago, because of an addition of a baby during the intervening period.
  • How old is baby ?
 

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3 years back the sum of ages was 80 for 5 persons and ave was 16,and now it will be 96 with same ave 16,thus 5*3=15,95 will be the sum of ages ,and the new born baby will be 1 year old
 
The sum age of 5 peoples ago 3 year was=80
Now at present age of five peoples=(3*5)+80=95
Add another baby in family but average was same as ago 3 years={(95+X)/6=16}
=95+X=96, value of x=1 year(that age of baby)
 
a total sum of ages of 5 membered family 3 years ago = 80
average age of each member let we consider as = 80/5= 16
present average age of family member is same...
sum of ages is 6 member (5+1 new baby)= 6*16= 96
80+5(3)= 95
therefore 6 th member i.e baby age is .. 96-95= 1 year
 
3 years ago sum of ages of all 5 members was 80 years
And average was 16 year

At present sum of ages of all 5 members and age of baby(x) is
80+(3*5)+x=95+x
Average at present is
(95+x)/6 =16(Given)
95+x=96
X=96-95=1

Hence age of baby is=x=1 year
 
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