Question

Two coin are tossed at the same time find the probability that one head is obtain?

Answer 1

Outcomes: $HH,TT,HT,TH$
favorable outcomes $=2$
and total outcomes $=4$

Let the probability of the event be $P\left(E\right),$ then
$P\left(E\right)=$ favorable outcomes/total outcomes
$2/4=1/2=0.5$

Hence, this is the answer.