Answer:
![(7)/(8)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/64i0w7z0rlvyn1723049yy8zn4ewvkmcaj.png)
Explanation:
We are give that three coins are flipped
Then , the sample space={HHH,HHT,THH,HTH,TTH,HTT,THT,TTT}
We have to find the probability of obtaining atleast one head
Atleas one head it means equal 1 or more than 1 head
Favorable cases={HHH,HHT,THH,HTT,HTH,TTH,THT}
Total number of cases=8
Number of favorable cases=7
Probability,P(E)=
![(Number\;of\;favorable\;cases)/(Total\;number\;of \;cases)](https://img.qammunity.org/2020/formulas/mathematics/college/wvrd90c8du9ms0poa5t10da930j77jvtul.png)
Using the formula
The probability of obtaining atleast one head=
![(7)/(8)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/64i0w7z0rlvyn1723049yy8zn4ewvkmcaj.png)