Question

Find the mean number of heads in three tosses of a fair coin.

Answer 1

When three coins are tossed the sample space is {HHH, HHT, THH, HTH, HTT, THT, TTH, TTT} 

∴ n(S) = 8 

Let X denote the number of heads when three coins are tossed. 

Then X can take values 0, 1, 2, 3