Question

in 7 years arin will be twice as old as she was 8 years ago .how old is arin now

Answer 1

let present age be x
7 years ahead = x + 7
8 years ago = x - 8
given 
x + 7 = 2 * (x - 8)
x + 7 = 2x - 16
7 + 16 = 2x - x
23 = x
she is 23 years old