Question

If a fair coin is tossed $5$ times, the probability that heads does not occur two or more times in a row is?

• A. $\frac{12}{2^5}$
• B. $\frac{13}{2^5}$
• C. $\frac{14}{2^5}$
• D. $\frac{15}{2^5}$

Answer 1

The correct option is B $\frac{13}{2^5}$

cases are

1. HTTTT
2. HTHTT
3. HTHTH
4. TTTTT
5. THTTT
6. TTHTT
7. TTTHT
8. TTTTH
9. HTTHT
10. HTTTH
11. THTHT
12. THTTH
13. TTHTH

probability $=\frac{13}{2^5}$