A bag contains 2 white marbles and 2 black marbles. If each of 2 girls and 2 boys randomly selects and keeps a marble, what is the probability that all of the girls select the same colored marble?  Choose one:  A) 1 / 35  B) 1 / 10  C) 1 / 3  D) 1 / 4  E) 1 / 5

Rationale: "first , total ways to select for all boys and girls , i . e 4 ! / ( 2 ! * 2 ! ) = 4 * 3 * 2 * 1 / 2 * 1 * 2 * 1 = 6 then there are one two way girls can have all same colors , either white or black . the number of ways in which 2 girls can select 2 white balls = 2 c 2 = 1 the number of ways in which 2 girls can select 2 black balls = 2 c 2 = 1 therefore , total favorable outcomes / total outcomes = 2 / 6 = 1 / 3 c"
Answer: C