Question

Two fair coins are tossed once. Then the number of elements in the sample space is

Answer 1

Since either coin can turn up Head $\left(H\right)$ or Tail $\left(T\right)$, the possible outcomes may be:
Head on both coins $=(H,H)=HH$
Head on first coin and Tail on the other $=(H,T)=HT$
Tail on first coin and Head on the other $=(T,H)=TH$
Tail on both coins $=(T,T)=TT$
Thus, the sample space is $S=HH,HT,TH,TT$
Clearly, $4$ elements are there in the sample space.