Question:
Two coins are tossed 1000 times and the outcomes are recorded as given below:
Now, if 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) $\frac{1}{5}$
Solution:
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
$\therefore P($ 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).