If each gift box in a store is sold at $80, the owner will make a profit of \$2700. If each gift box is sold at \$60 instead, he will make a profit of \$900.

(a) How many gift boxes are there?

(b) What is the cost price of each gift box?

(a) 70

(b) \$40

(b) \$40

(a) 80

(b) \$45

(b) \$45

(a) 90

(b) \$50

(b) \$50

(a) 100

(b) \$55

(b) \$55

None of the above