Question

A box contains 20 cards, numbered from 1 to 20. A card is drawn from the box at random. Find the probability that the number on the drawn card is even.

Answer 1

Given: A box contains cards numbered 1 to 20; one card is drawn at random.

Step-wise calculation:

1. Total number of possible outcomes = 20 (cards 1 through 20).

2. Favourable outcomes = Even numbers between 1 and 20

= 2, 4, 6,...,20

⇒ 10 numbers

3. Probability = `"Number of favourable outcomes"/"Total outcomes"`

= `10/20`

= `1/2`

The probability that the drawn card is even is `1/2` or 0.5, i.e. 50%.