the difference of ages between 2 sisters is 10 years, 15 years ago elder 1 was twice as old as younger age. find the both present age?
b-a=10
(b-15) = 2(a-15)
(a+10-15) = 2(a-15)
a-5 = 2a-30
a = 25
So, the sisters are 25 and 35
check:
15 years ago they were 10 and 20