Question

The possible outcomes for tossing a coin four times are shown below.

1. T-T-T-T 5. T-H-T-T 9. H-T-T-T 13. H-H-T-T
2. T-T-T-H 6. T-H-T-H 10. H-T-T-H 14. H-H-T-H
3. T-T-H-T 7. T-H-H-T 11. H-T-H-T 15. H-H-H-T
4. T-T-H-H 8. T-H-H-H 12. H-T-H-H 16. H-H-H-H
Tails = T Heads = H

If a coin is tossed four times, what is the probability of getting exactly two heads?