Question 1062268

the sum of my parents' ages is 70. Twenty years ago, my father was 4 years older than my mother.  how old are they now
<pre>Let father's age be F
Then mother's age = 70 - F
Father was 4 years older than mother, 20, 10, 5, 2, 15 years ago. The point is, while alive, the father will always be 4 years older than the mother. 
Hence, we get mother's age as: F - 4
We then have: 70 - F = F - 4
- F - F = - 4 - 70
- 2F = - 74
F, or father's age is: {{{highlight_green(matrix(1,3, (- 74)/(- 2), or, 37))}}}
Mother's is: 70 - 37, or 37 - 4 = {{{highlight_green(matrix(1,2, 33, years-old))}}}