Question 1117309: A man is 36 years old, and his sister is 29 years old. How many years ago was it when the man was twice as old as his sister? Found 2 solutions by solver91311, greenestamps:Answer by solver91311(24713) (Show Source):
Let be the number of years ago the brother was twice as old as the sister. Since the brother is 36 now, he was then. Likewise, the sister was then. Also, years ago two times her age was his age:
Solve for
John
My calculator said it, I believe it, that settles it
If you need an algebraic solution, the one from the other tutor is fine. And it is good to know how to solve problems like this using algebra.
But if you just need to solve the problem, logical analysis is much faster.
The man is 36 and his sister is 29; the difference in their ages is 7.
So when the man was twice as old as his sister, she was 7 and he was 14.
Since the man is now 36, that was 22 years ago.
