Question: At the patisserie, a single layer cake slice is $4 and a double layer cake slice is $7. Dusty buys 7 single layer cake slices and 5 double layer cake slices. If he pays with a $100 bill, how much change does he receive? Think carefully first, then make a decision:
Single layer cake slices cost $4 x 7 = $28. Double layer cake slices cost $7 x 5 = $35. All the cake slices together cost $28 + $35 = $63. He will receive change of $100 - $63 = $37. So the answer is 37.