Question 762997
The total of the ages of 3 people is 80 years.
 what was the total of their ages 3 years ago?
:
a + b + c = 80
(a-3) + (b-3) + (c-3)
a+b+c - 9 = ?
replace a+b+c with 80
80 - 9 = 71 is the total 3 yrs ago