Elizabeth bought 6 feet of elastic at $0.84 per foot. she also bought 18 inches of ribbon at $1.62 per foot. explain how to calculate the total cost of elizabeth's purchase. a. step 1 divide $0.84 by 6 to calculate the cost of the elastic. step 2 divide $1.62 by 18 to calculate the cost of the ribbon. step 3 add the two amounts together. b. step 1 multiply $0.84 by 6 to calculate the cost of the elastic. step 2 multiply $1.62 by 18 to calculate the cost of the ribbon. step 3 add the two amounts together. c. step 1 divide $0.84 by 6 to calculate the cost of the elastic. step 2 convert 18 inches to feet, and then divide $1.62 by 1.5 to calculate the cost of the ribbon. step 3 add the two amounts together. d. step 1 multiply $0.84 by 6 to calculate the cost of the elastic. step 2 convert 18 inches to feet, and then multiply $1.62 by 1.5 to calculate the cost of the ribbon. step 3 add the two amounts together.