A craft store buys 50 yards of satin ribbon for 13.50. The store. The store sells the ribbon by the foot.A customer can purchase 5 feet of ribbon for $0.80. How much profit does the craft store earn if it sells 45 yards of the ribbon and scraps the rest?

Convert 45 yards of ribbon to feet through proper conversion factor. 

   (45 yards)(3 ft / 1 yard) = 135 feet

Divide this number by 5 to determine the number of 5-ft ribbon that customers can purchased.

     n = 135 ft / 5 ft = 27

Then, multiply by $0.80.

    R = (27)($0.80) = $21.6

The profit is equal to $21.6 and $13.50,

     P = $21.6 - $13.50 = $8.1

Answer: $8.1