Question

HELP ME ! A fair coin is tossed three times in succession. The sample space is​ shown, where H represents a head and T represents a tail. Find the probability of getting exactly zero tails.

Answer 1

0.125

Explanation:

For a fair coin, H and T is the same probability. To get zero tails, we need to toss a head, then a head, and again a head - each time we succeed with probability of 0.5, so succeeding 3 times happens 0.5^3 of the time = 0.125

Alternatively, look at all the options:

HHH

HHT

HTH

HTT

THH

THT

TTH

TTT

Only one option has no tails, and because the coin is fair, each option is equally probable, so the probability of HHH is 1/8 = 0.125