Question

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

Number of heads	2	1	0
Frequency	200	550	250

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) $\frac{1}{5}$

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) = $\frac{\mathrm{Number}\mathrm{of}\mathrm{times}\mathrm{of}\mathrm{getting}\mathrm{at}\mathrm{most}\mathrm{one}\mathrm{head}}{\mathrm{Total}\mathrm{number}\mathrm{of}\mathrm{times}\mathrm{two}\mathrm{coins}\mathrm{are}\mathrm{tossed}}=\frac{800}{1000}=\frac{4}{5}$

Hence, the correct answer is option (b).