SOLUTION: seven years ago when anna was born, mandy was 2 times as old as rachel. when anna turns 15 she will be three fifths of rachel's age. what is the sum of their current ages

Question 847771: seven years ago when anna was born, mandy was 2 times as old as rachel. when anna turns 15 she will be three fifths of rachel's age. what is the sum of their current ages
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!

let m = Mandy's present age
let r = Rachel's present age
:
Seven years ago when Anna was born, Mandy was 2 times as old as Rachel.
m - 7 = 2(r-7)
m - 7 = 2r - 14
m = 2r - 14 + 7
m = 2r - 7
when Anna turns 15 she will be three fifths of Rachel's age.
From the information given, we know that Anna will turn 15 in 8 yrs
(r+8) = 15
3(r+8) = 5(15)
3r + 24 = 75
3r = 75 - 24
3r = 51
r = 51/3
r = 17 yrs is Rachel's age
then
m = 2(17) - 7
m = 34 - 7
m - 27 yrs is Mandy's age
:
What is the sum of their current ages?
We know Anna is now 7 yrs old
7 + 27 + 17 = 51
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