The probablity of getting one head on tossing one coin = 1/2
Sample space on tossing three coins are;
HHH TTT
HHT TTH
HTH THT
THH HTT
Total number of sample space = 8
Favorable outcome is getting head three
Number of situation when we get three head = 1
Probaility = 1/8
1/8 = 0.125
Probability of obtaining exactly three heads when flipping three coins is 0.125