<PRE><B>Question 1089235</B>
 Three years ago the average age of a family of 5 members is 27 years.
 On the addition of a child to the family, the average age of the family is still 27 years.
 Find the present age of the child.
:
let t = total of their ages 3 yrs ago
{{{t/5 = 27}}}
t = 5*27
t = 135
In 3 yrs, five people would add 15 yrs to the total; 150
:
let c = age of the child
we now have 6 people in the family
{{{((150 + c))/6}}} = 27
150 + c = 27 * 6
150 + c = 162
c = 162 - 150
c = 12 yrs is the age of the child  </PRE>