Question

Two coins are tossed 1000 times and the outcomes are recorded as given below:

$\begin{array}{cccc}\text{Number of heads}& 2& 1& 0\\ \text{Frequency}& 200& 550& 250\end{array}$

Now, it two coins are tossed at random, what is the probability of getting at most one head?

(a) $\frac{3}{4}$

(b) $\frac{4}{5}$

(c) $\frac{1}{4}$

(d) $\frac{1}{5}$

Answer 1

Total number of times two coins are tossed = 1000
Number of times of getting at most one head = Number of times of getting 0 heads + Number of times of getting 1 head = 250 + 550 = 800
∴ P(Getting at most one head)
=$\frac{\text{Number of times of getting at most one head}}{\text{Total number of times two coins are tossed}}$=$\frac{800}{1000}$=$\frac{4}{5}$
Hence, the correct answer is option (b).