At one store, matt saved $15 with a coupon for 30% off his total purchase. at another store, the 24$ he spent on books is 48% of his total bill. how much did matt spend in all at he stores ?

Frank has a devised a formula for his catering business that calculates the number of meatballs he needs to prepare. the formula is m=4a+2c, where c=number of children; m=number of meatballs; a=number of adults. how many meatballs are required for a party of 10 adults and 5 children?