A die is tossed thrice. Find the probability of getting an odd number at least once.
A die is tossed thrice. Find the probability of getting an odd number at least once.

Given: A die is tossed three times.

Then the sample space S={1,2,3,4,5,6}

Let \mathrm{P}(\mathrm{A})= probability of getting an odd number in first throw.

\Rightarrow P(A)=3 / 6=1 / 2 .

Let \mathrm{P}(\mathrm{B})= probability of getting an even number.

\Rightarrow P(B)=3 / 6=1 / 2

Now, probability of getting an even number in three times =1 / 2 \times 1 / 2 \times 1 / 2=1 / 8

So, the chances of obtaining an odd number at least once

=1 – probability of getting an odd number in no throw

=1 – probability of getting an even number in three times

=1-1 / 8

\therefore Probability of getting an odd number at least once =7 / 8