On her birthday, a girl receives a giant box of crème filled chocolates from a secret admirer. She only likes the ones with fruit flavored fillings and won't eat the others. The box says that 25% of the chocolates have fruit fillings. If she keeps choosing chocolates and biting into them, how many should she expect to reject until finding the first fruit flavored one?

4 chocolates

Step-by-step explanation:

Since the problem states that the girl received a "giant box", this situation can be treated as if there is replacement, since the change in the probability  of getting a chocolate with fruit filling would be minimal after picking a random chocolate.

Therefore, the expected number of choices she has to make before finding the first fruit flavored one is obtained by dividing 1 by the probability of a fruit flavored one:

She should expect to choose 4 chocolates.