Refer to Example 3.29. Suppose the consumer testing service is to choose the top 3 laundry detergents from the group of 10, but is not to rank them.

a. In how many different ways can the testing service choose the 3 brands to be designated as top detergents?

b. Assuming that the testing service makes its choice by a random selection and that company X has 2 brands in the group of 10, what is the probability that exactly 1 of company X’s brands is selected in the top 3? At least 1?