Respuesta :
Let Sister's age now = s
So Larry is now s + 8
In THREE Years Sister = s + 3
Larry = {s + 8} + 3
But We are told that he will be TWICE as old as Sister is NOW!!!
So s + 11 = {2s}
Solve s = 11
So Sister is ELEVEN Years old and Larry is NINETEEN Years old.
Lets say that Larry's sister is x
Then Larry is x+8
In 3 years Larry will be x+11 or 2(x+3)
So x+11=2(x+3)
x+11=2x+6
x=5
Larry is 13, his sister is 5