In a room filled with 8 people, 6 people have exactly 2 siblings in the room and 2 people have exactly one sibling in the room. If two individuals are selected from the room at random, what is the probability that those two individuals are NOT siblings? Choose the correct choice from the following choices:  A) 5/8  B) 3/8  C) 3/5  D) 2/3  E) 3/4
The 8 people consist of two sets of 3 siblings and 1 set of 2 siblings.   The number of ways to choose 2 people is 8C2 = 28.   The number of ways to choose 2 from the first group of siblings is 3C2 = 3.   The number of ways to choose 2 from the second group of siblings is 3C2 = 3.   The number of ways to choose 2 from the third group of siblings is 2C2 = 1.   The number of ways to choose 2 people who are siblings is  3+3+1= 
<gadget id="calculator"> 3+3+1</gadget>
<output>7</output>
7.   The number of ways to choose 2 people who are not siblings is   28-7= 
<gadget id="calculator">  28-7</gadget>
<output>21</output>
21.   P(the two people are not siblings)= 21/28 = 3/4   The answer is 3/4.
<result>E</result>
In a room filled with 8 people, 6 people have exactly 2 siblings in the room and 2 people have exactly one sibling in the room. If two individuals are selected from the room at random, what is the probability that those two individuals are NOT siblings?