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

$\begin{array}{1 1}1/8 \\ 7/8 \\ 5/8 \\ 1/4 \end{array}$

Toolbox:
• The probability of getting an odd (or even) number at least once in a roll of die = 1 - probability of not gettiing an odd (or even) number in any of the throws.
In one roll of die, the probability of getting an odd (or even) number is $\large\frac{3}{6} = \frac{1}{2}$ as there are three odd numbers and three even numbers.
Therefore, probability of getting an even number on three rolls of the die = $\large\frac{1}{2}$ $\;\times$ $\large\frac{1}{2}$ $\;\times$ $\large\frac{1}{2}$ = $\large\frac{1}{8}$
The probability of getting an odd (or even) number at least once in a roll of die = 1 - probability of not gettiing an odd (or even) number in any of the throws.
$\Rightarrow$The probability of getting an odd number at least once in a roll of die = 1 - probability of not gettiing an odd (i.e. getting only an even on all rolls) number in any of the throws = 1 - $\large\frac{1}{8} = \frac{7}{8}$