A department store is running a promo one Saturday by giving out coupons for $10 of free merchandise. However, one-third of customers spend $40, and one-third spend$75. The remainder of customers who come in the store do not take advantage of the promo at all.

Question

A department store is running a promo one Saturday by giving out coupons for $10 of free merchandise. However, one-third of customers spend $40, and one-third spend$75. The remainder of customers who come in the store do not take advantage of the promo at all.
A) find expected value for the dept store on their promo.
B) if the store has 712 customers on the promo Saturday, what is their net expected profit at the end of the day?