Answer:
[tex]Sets = 27[/tex]
Step-by-step explanation:
Given
[tex]Coin = 1[/tex]
[tex]Toss = 5[/tex]
Required
Number of outcomes with at most 3 heads
First, we list out the sample space of a toss of coin 5 times
[tex](HHHHH)[/tex], [tex](HHHHT)[/tex], [tex](HHHTT)[/tex], [tex](HHTTT)[/tex], [tex](HTTTT)[/tex], [tex](TTTTT)[/tex], [tex](TTTTH)[/tex], [tex](TTTHH)[/tex], [tex](TTHHH)[/tex], [tex](THHHH)[/tex], [tex](HTHTH)[/tex], [tex](THTHT)[/tex], [tex](HHTHH)[/tex], [tex](TTHTT)[/tex], [tex](HTTHT)[/tex], [tex](THHTH)[/tex], [tex](THHHT)[/tex], [tex](HTTTH)[/tex], [tex](THHTT)[/tex], [tex](HTTHH)[/tex], [tex](HHTTH)[/tex], [tex](TTHHT)[/tex], [tex](TTHTH)[/tex], [tex](HHTHT)[/tex], [tex](HTHTT)[/tex], [tex](THTHH)[/tex], [tex](THTTH)[/tex], [tex](HTHHT)[/tex], [tex](HTHTT)[/tex], [tex](THTHH)[/tex], [tex](HHHTH)[/tex], [tex](TTTHT)[/tex]
Next, we list out all outcomes with at most 3 heads
, , [tex](HHHTT)[/tex], [tex](HHTTT)[/tex], [tex](HTTTT)[/tex], [tex](TTTTT)[/tex], [tex](TTTTH)[/tex], [tex](TTTHH)[/tex], [tex](TTHHH)[/tex], , [tex](HTHTH)[/tex], [tex](THTHT)[/tex], , [tex](TTHTT)[/tex], [tex](HTTHT)[/tex], [tex](THHTH)[/tex], [tex](THHHT)[/tex], [tex](HTTTH)[/tex], [tex](THHTT)[/tex], [tex](HTTHH)[/tex], [tex](HHTTH)[/tex], [tex](TTHHT)[/tex], [tex](TTHTH)[/tex], [tex](HHTHT)[/tex], [tex](HTHTT)[/tex], [tex](THTHH)[/tex], [tex](THTTH)[/tex], [tex](HTHHT)[/tex], [tex](HTHTT)[/tex], [tex](THTHH)[/tex], [tex](TTTHT)[/tex]
So, the number of set is:
[tex]Sets = 27[/tex]
