A water-efficient washer costs $400 more than a regular washer and saves 100 l of water for each load. if water costs $5 per 1,000 l and you wash 100 loads each year, how many years will it take you to recoup the extra cost of the machine?
8 years because its uses 100l per load and you wash 100 per year you multiply and get 10,000 which divided by 1,00 its 10 so 10 x 5 = 50 so you save 50 per year and its 400 dollars more so 50 x 8 years will be 400