the souvenir store charges Php 15.00 per keychain for orders amounting to 50 or fewer keychains, Php 12.50 per keychain for orders of 70 or fewer orders but more than 50 keychains,and Php 10 per keychains for orders of more than 75 keychains.Which function best represents the cost K(x) of the x number of keychains?
