math
posted by justin on .
this year Ben is 4/7 as old Glen. Fifteen years fromnow Ben will be 3/4 as old as Glen. At that time he sum of thier ages will be 63. How old are Ben and Glen now?

You have more information than is needed
let Glen's present age be x
then Ben's present age is 4x/7
in 15 years:
Glen will be x+15
Ben will be 4x/7 + 15
We are told
x+15 + 4x/7+15 = 63
7x + 105 + 4x + 105 = 441
11x = 441  210
11x = 231
x = 21
So Glen is now 21 and Ben is now 12
The fact that "Fifteen years fromnow Ben will be 3/4 as old as Glen" was not needed, but confirms our answer.