Referring to the Fig, Mrs. Hawkins took four slips of paper
and wrote a different student's name on each. Two of the names were
boys and two girls. She put the four slips of paper in a bag and said
she is going to draw two slips out. She then drew the tree diagram
to show the different outcomes that are possible. "B" represents a
boy's name and "G" represents a girl's name. What is the theoretical
probability that the teacher draws two names that are the opposite sex?
a. 2/3 c. 1/3
b. 3/4 d. 7/12