SOLUTION: if peter is 7 years older than sharon and john is twice as old as peter, work out how old peter is if the average of their ages is 19

Question 352560: if peter is 7 years older than sharon and john is twice as old as peter, work out how old peter is if the average of their ages is 19
Found 2 solutions by mananth, josmiceli:
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
let sharon be x years
Peter = x+7
John = 2(x+7)
...
Average age = 19
so sum of their ages = 3*19 = 57
x+x+7+2x+14=57
4x+21=57
4x=57-21
4x=36
x= 9 sharon's age
..
peter's age = x+7 = 16
..
John's age = 2(x+7)=32
...
m.ananth@hotmail.ca

Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = Peter's age
Let = Sharon's age
Let = John's age
-----------------
given:
(1)
(2)
(3)
------------------
From (1):

Substitute (1) and (2) in (3)
(3)

Peter is 16
check answer:

and

and
(3)
(3)

OK
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