SOLUTION: average age of a boy and a girl is 14 yrs. The average age of the same boy, the girl and her twin sister is 16 yrs. What is the boy's age?

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Question 1077694: average age of a boy and a girl is 14 yrs. The average age of the same boy, the girl and her twin sister is 16 yrs. What is the boy's age?
Answer by amfagge92(93)   (Show Source): You can put this solution on YOUR website!
let their ages be a , b and 2b
a+b/2=14....i
a+2b/3=16..ii
solving we have
a+b=28....iii
a+2b=48...iv
a=28-b......v
subtitute a in eqn iv
28-b+2b=48
b=20
subtitute b in enq v
a=28-20
a=8.
the boy's age is 8.

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