Haryana Police Constable Model Paper 1

Given:
Three unbiased coins are thrown simultaneously
Concept Used:
Probably of an event $=\frac{\mathrm{Desire}\mathrm{event}}{\mathrm{Total}\mathrm{possible}\mathrm{number}\mathrm{of}\mathrm{events}}$
Calculation:
In a single throw of a coin, two results can happen,
One is head, denoted by H
And another is tail, denoted by T
In the single throw of one coin total possible outcome = $2^1$ = 2
In a single throw of three coins total possible outcome = $2^3$ = 8
Possible results are {HHH, HHT,HTH, HTT, THH, THT, TTH, TTT}
From the above, at least two head cases are {HHH, HHT, HTH, THH} = 4
The probability of getting at least two head is $\frac{4}{8}$ = $\frac{1}{2}$
∴ The probability of getting at least two head is $\frac{1}{2}$