Question

A game consists of tossing a 1 rupee coin three times, and nothing its outcomes each time. Find the probability of getting

(i) 3 Heads,

(ii) at least 2 tails.

Answer 1

When a coin is tossed three times, all possible outcomes are 

HHH,HHT,HTH,THH,HTT,THT,TTH and TTT.

The number of total outcomes = 8.

(i) The outcomes with three heads is HHH.

the number of outcomes with three heads = 1

Therefore, P(getting at least two tails) = \(\frac{number\, of\,favorable\,outcomes}{number\,of \,all\,possible\,outcomes}\) = \(\frac{4}5\) = \(\frac{1}2\)

Thus, the probability of getting at least two tails is \(\frac{1}2\).