Question

an advertisement claims that a 5-pound box of detergent will wash 20 loads of laundry a 5 pound box cost $3.50 a 15 pound box cost $10.00 how much will you save per load if you buy a 15 pound box

Answer 1

5 pound box: cost per wash = 3.50/20 = $0.175 per wash

15 pound box: cost per wash = 10/(3 x 20) = $0.167 per wash

the 15 pound wash will save 0.175 - 0.167 = $0.008 per wash