A nickel is flipped and a dime is flipped.

1. What is the probability of obtaining exactly one head?

A bag contains five balls numbered 0 through 4. Two balls are chosen at random in succession. The first ball is replaced before the second is chosen.

1. What is the probability that the first ball has an odd number?

2. What is the probability that the second ball has an odd number?

3. What is the probability that both balls have odd numbers?

4. What is the probability that neither ball has an odd number?