6.7 (1) Mary's utility function is U(b, c) = b | 100C 02, Where b is the number of silver bells in her garden and c is the number of cockle shells. She has 500 square feet in her garden to allocate between silver bells and cockle shells. Silver bells each take up 1 square foot and cockle shells each take up 4 square feet. She gets both kinds of seeds for free. (a) To maximize her utility, given the size of her garden, Mary should plant 308 silver bells and 48 cockle shells. (Hint: Write down her \"budget constraint\" for space. Solve the problem as if it were an ordinary demand problem.)