Question

A number is selected at random from the numbers from 1 to 30. Find the probability that the selected number is either even or odd.

Answer 1

Total no. of outcomes = 30
Even numbers upto 30 are (2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30)
Odd numbers upto 30 are (1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29)

Total no. of favourable outcomes(both even and odd numbers) = 30

Let $E$ be the event of getting a number which is either odd or even.

$\text{Probability P(E)}$ = $\frac{\text{Number of outcomes favorable to E}}{\text{Number of all possible outcomes of the experiment}}$

$\therefore$ P(selected no. is either even or odd)$=\frac{30}{30}=1$