Question

Two coins are tossed simultaneously. What is the probability that the second coin would show a tail given that the first coin has shown a head?

• A. $0.50$
• B. $0.25$
• C. $0.75$
• D. $0.125$

Answer 1

The correct option is B $0.25$

Given: Two coins are tossed simultaneously.

To find: the probability that the second coin would show a tail given that the first coin has shown a head

Sol: The sample space for two coins is $\{HH,HT,TH,TT\}$, $n\left(S\right)=4$

Favourable outcomes for the first coin head and second coin showing tail are $HT$, $n\left(E\right)=1$

Hence, the probability that the second coin would show a tail given that the first coin has shown a head is $\frac{n\left(E\right)}{n\left(S\right)}=\frac{1}{4}=0.25$