Question 802918: darren is 8 years older then his sister. in three years he will be twice as old as she will be then. how old is each now Answer by thejackal(72) (Show Source):
You can put this solution on YOUR website! let his sister's age now be S
such that Darren's age now can be given as D = S + 8
thus
in 3 years D + 3
he will be twice as old as she will be then (S + 3)*2
so
D + 3 = (S + 3)*2
(S + 8) + 3 = 2S + 6
S + 11 = 2S + 6
11 - 6 = S = 5;
D = 5 + 8 = 13