math
posted by Jim .
It takes a florist 3h 15min to make 3 small centerpieces and 3 large cebterpieces. It takes 6h 20min to make 4 small centerpieces abd 7 large centerpieces. How long does it take to make each small centerpiece and each large centerpiece? Write and solve a system of equations to find your answer.

if the times required are x and y for small and large, respectively,
3x+3y = 3 1/4 = 13/4
4x+7y = 6 1/3 = 19/3
clearing fractions, we have
12x+12y = 13
12x+21y = 19
subtract top from bottom to get
9y = 6
y = 2/3
so,
small takes 25 min
large takes 40 min