The probability is really p = 0.5 (since 1/2 = 0.5)
Now look for the value of p = 0.5 (in green). Below is the answer (in red)
n x 0.01 0.05 0.10 0.20 0.30 0.40 0.50 0.60 0.70
5 0 .951 .774 .590 .328 .168 .078 0.031 .010 .002
Answer: So the probability of getting exactly 0 heads in 5 flips is approximately 0.031