Question

a coin is tossed twice in a row. what is the probability of tossing \heads\ both times?
a $\frac{1}{4}$
b $\frac{1}{2}$
c $\frac{3}{4}$
d $\frac{1}{1}$

Explanation:

Step1: Probability of single - head toss

The probability of getting heads in a single coin - toss is $P(H)=\frac{1}{2}$.

Step2: Probability of two - head tosses

Since the two coin - tosses are independent events, the probability of getting heads twice is $P(H_1\cap H_2)=P(H_1)\times P(H_2)=\frac{1}{2}\times\frac{1}{2}=\frac{1}{4}$.

Answer:

A. $\frac{1}{4}$