Combined rates
Susan = 2 car / 3 hr
= 2/3
Joe = 3 car / 4 hr
= 3/4
add the rates to get the new combined rate as 17 cars in "t" hours.
2/3 + 3/4 = 17/t
Need common denominator
2/3(4/4) + 3/4(3/3) = 17/t
8/12 + 9/12 = 17/t
17/12 = 17/t
see that "t" is 12 hours
91 IS THE AREAS OF THE SIX RECTANGLES
