math
posted by Joe on .
James is 15 years older than Sue. In 12 years James will twice Sue's age. How old are James and Sue?

present:
Sue  x
James  x+15
in 12 years:
Sue  x+12
James  x+15 + 12 = x + 27
james is twice as old as Sue
x+27 = 2(x+12)
x+27 = 2x + 24
x = 3
x = 3
Sue is now 3 and James is now 18
check:
in 12 years, Sue will be 15
James will be 30
Will he be twice as old as her ?? YES