Question

An advertisement claims that a 5-pound box of detergent will wash 20 loads of laundry. A 5-pound box costs $3.50. A 15-pound box costs $10.00. About how much will you save per load if you buy the 15-pound box?

Answer 1

With the 15 pound box you can wash 3x the amount of laundry for 30 cents less .

Explanation:

$3.50 x3 will do the same amount of laundry but will cost more.

so your better buy would be the 15 pound box. :]