From a seven-member dance group, four will be chosen at random to volunteer at a youth dance event. If Kori and Jason are two of the seven members, what is the probability that both will be chosen to volunteer?
Choose the correct choice from the following answers:
A) 1/21
B) 1/7
C) 4/21
D) 2/7
E) 3/7
Total number of ways to choose 4 out of 7 = 7C4 = 35.   Number of ways to choose 2 (any but Kori and Jason) out of 5 (excluding Kori and Jason) = 5C2 = 10.   P = favorable/total = 10/35 = 2/7.   Answer: 2/7.
<result>D</result>
From a seven-member dance group, four will be chosen at random to volunteer at a youth dance event. If Kori and Jason are two of the seven members, what is the probability that both will be chosen to volunteer?