In a senior class, 17% play chess, 31% play checkers, and 11% play both. Find the probability of a senior who plays chess also plays checkers

Plz i want answer and i would appreciate it is is a b c or d

Plz which expression is equivalent to the expression below?

Florence price's brownies and more sells all types of cookies and pastries. on tuesdays, they markdown all brownies 75% to a sale of $1.50 a dozen. find the selling price and the markdown of a dozen brownies.