John is 4 times as old as Martha. Eight years ago the sum of their ages was sixty-nine. How old are they now?
A)John is 88; Martha is 22
B)John is 56; Martha is 14
C)John is 60; Martha is 15
D)John is 68; Martha is 17
E)John is 76; Martha is 19

Question

Quizplus · Accepted Answer

Let Martha's age be x
John's age = 4x
8 years ago: 
Martha's age = x - 8
John's age = 4x - 8
Their sum = 69
(x - 8) + (4x - 8) = 69
5x - 16 = 69
5x = 85
x = 17
Martha's age now = 17
John's age now = 4x = 68
Therefore, answer is D

John Is 4 Times as Old as Martha