There are 2 types of Happy Meal toys in the McDonald's. Each of the toy type will be given with equal chances to a customer who buys the Happy Meal. Suppose that there is only one toy type that has the castle and Little Mary wants to get the castle very much. Let X denotes the random variable indicating the number of Happy Meals Little Mary should buy till she gets the castle. Then, the expected value ofX should be 0 5/2 01 O2 0 3/2