Question

Determine the probability P or an estimate of it for each of the following events.

i. At least one head appears in two tosses of a fair coin

ii. The number it appears in two tosses of a pair of fair die

Answer 1

i.  

When a fair coin is tossed twice,

S = {HH, HT, TH, TT}

Thus, total n, of outcomes = 4

For at least one head to appear, the possible cases will be – HH, HT, TH

Thus, favorable outcomes = 3

Now, 

Probability = $\frac{no. of favorable outcomes}{/ total no. of outcomes}$

                 = $\frac{3}{4}$

ii.

(ii) part of the question is not correctly asked. You've not mentioned the number for which probability has to be calculated.