Marcos's grandparents gave Marcos a visa gift card of $250. Marcos decided to use his gift card to buy himself a fifteen dollar lunch every day.
Marcos’s parents also gave Marcos a gift card but for his birthday. The gift card balance is represented by the equation: 50y + 55x = 500
(a. What equation represents Marcos's spendings that include his gift card?
(b. Will Marcos’ grandparent's and parents’ gift cards ever have the same balance?
(c. Determine the number of solutions Marcos’ parents and grandparents have.