SOLUTION: I am twice as old as my sister was when I was the age that she is now. The sum of our present ages is 49. How old are we?

Question 947268: I am twice as old as my sister was when I was the age that she is now. The sum of our present ages is 49. How old are we?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
let y = your age
let s = sister's age
:
I am twice as old as my sister was when I was the age that she is now.
y = 2(s - (y-s))
y = 2(s - y + s)
y = 2(2s - y)
y = 4s - 2y
y + 2y = 4s
3y = 4s
y = s
The sum of our present ages is 49.
y + s = 49
replace y with s
s + s = 49
s = 49
Multiply both sides by 3/7
s = 21 is sister's age
then
y + 21 = 49
y = 28 yrs is your age
:
:
See if that makes sense in the statement
the difference of the ages is 7 yrs
" I am twice as old as my sister was when I was the age that she is now."
28 = 2(21 - 7)
28 = 2(14)

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