Question

Three coins are tossed simultaneously for 150 times and the number of heads are recorded as shown below in the table:

Number of heads	Frequency
0	25
1	45
2	50
3	30

Find the probability of atleast 2 heads appearing.

• A. 0.45
• B. 0.33
• C. 0.533
• D. 0.6

Answer 1

The correct option is C 0.533

We know, for an event E,
$P\left(E\right)=\frac{\text{Number of trials in which the event happened}}{\text{Total number of trials}}$

Here, the event E is atleast 2 heads appearing, which happens 50 + 30 = 80 times.
Given, total number of trials (or tosses) is 150.
Therefore,
$P\left(E\right)=\frac{80}{150}=\frac{8}{15}=0.533$