<PRE><B>Question 329837</B>
the average age of a group of 9 boys is 8 years 6 months.
find the total age of nine boys.
Convert 8 yrs 6 months to 8.5 yrs
9 * 8.5 = 76.5 yrs
:
If a tenth boy aged 9 year 4 months joins the group, what will be the average age of the ten boys?
Convert  9 yrs 4 months to 9.33 yrs
{{{(76.5 + 9.33)/10}}} = 8.583 yrs, or 8 + .583(12) = 8 yrs 7 months




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