There are 20 families living in the Willbrook Farms Development. Of these families, 10 prepared their own federal income taxes for last year, 7 had their taxes prepared by a local professional, and the remaining 3 by H&R Block. a) What is the probability of selecting a family that prepared their own taxes? b) What is the probability of selecting two families, both of which prepared their own taxes?

a) 1/2

b) 9/40

Step-by-step explanation:

Given

Total number of families living in Willbrook Farms Development = 20

Number of families preparing their own federal income taxes for last year = 10

Number of families for which taxes were prepared by a local professional = 7

Number of families for which taxes were prepared by H&R Block = 3

a) Probability of selecting a family that prepared their own taxes = 10/20 = 1/2

b) The probability of selecting two families, both of which prepared their own taxes

10/20 * 9/20 = 9/40

c. (3,2,6) is the answer.

x = 3 ± √(5+y)