Carlson Jewelers permits the return of their diamond wedding

Carlson Jewelers permits the return of their diamond wedding rings, provided the return occurs within two weeks of the purchase date. Their records reveal that 10 percent of the diamond wedding rings are returned. Five different customers buy five rings. What is the probability that exactly 3 will be returned?

P none returned = (1-.1)^5= .9^5=0.59049 or 59.049%