Question

please help me by answering the question

Answer 1

the sample space of toss 2 coins and a fair coin simultaneously:

s:{HHHHHHH,HHHHHHT,HHHHHTT,HHHHHTT,HHHTTTT,HHTTTTT,HTTTTTT,TTTTTTT}

n(s):

let A be the event getting at least one tail

A:{HHHHHHT,HHHHHTT,HHHHHTT,HHHTTTT,HHTTTTT,HTTTTTT,TTTTTTT}

n(A):7

p(A):n(A)/n(s)=7/8

Therefore the probability of getting at least one tail is 7/8