Three girls and two boys are planning to meet for a party. What is the probability that the first two to arrive are the boys?

Answer 1

The probability that the first to arrive is a boy is 2 out of 5, which leaves 1 boy and 3 girls. The probability then that the second to arrive will be a boy is thus 1 out of 4. The probability that the boys will be the first two to arrive will be the product of those 2 probabilities: 2/5 * 1/4 = 1/10.