Question 764374: tony is 21 years older than his sister. in 10 years he will be twice as old as his sister. how old is each of them Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! tony is 21 years older than his sister. in 10 years he will be twice as old as his sister. how old is each of them
-----
Equations:
t = s + 21
t+10 = 2(s+10)
-----
Substitute for "t" and solve for "s":
s+21+10 = 2s+20
s + 31 = 2s + 20
s = 11 (sister's age now)
---
Solve for "t":
t = s + 21
t = 32 (tony's age now)
===================
Cheers,
Stan H.
===============
(