Question 150905
Write an equation for each statement:
:
"The sum of the ages of Art, Ben, and Cal is 59."
 a + b + c = 59
:
"Art is 1 year older than Cal,"
a = c + 1
:
"Cal is 1 year younger than Ben."
c = b - 1
or
b = c + 1
;
Substitute for a and b and find in the total age equation, find c
(c+1) + (c+1) + c = 59
3c + 2 = 59
3c = 59 - 2
c = {{{57/3}}}
c = 19 yrs
:
a = 20; b = 20
: 
Which of these people were teenagers 7 years ago?
: 
c would be 12, a & b would be teenagers