The average age of a group of 25 girls is 10year. If one girl, aged 12 years and 4 months joins the group, find the new average age of the group
-
A.
10.1 years -
B.
9.3 years -
C.
8.7 years -
D.
8 . 3 years
Explanation
x = 10 ; 10 = (frac{x}{25})
x = 250
x = (frac{250 + 12.4}{26})
x = 10.09
x = 10.1 years