15. Puto balanghoy or steamed cassava cake is traditionally made in the Visayas region using basic ingredients such as cassava, brown sugar and grated coconut. Marvin is selling a puto balanghoy in the function of f(x) 10x, how much is Marvin's income if a customer wants to buy a total of 50 pieces? A. Php450 C. Php550 B. Php500 D. Php600