Question

A box contains 30 cards, numbered from 1 to 30. A card is drawn from the box at random. Find the probability that the number on the drawn card is a multiple of 7.

Answer 1

Given: A box contains 30 cards numbered 1 to 30. A card is drawn at random; find the probability the number is a multiple of 7.

Step-wise calculation:

1. Total possible outcomes = 30 (one for each card).

2. Multiples of 7 between 1 and 30 are 7, 14, 21, 28.

Number of favourable outcomes = 4.

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

= `4/30`

4. Simplify the fraction: `4/30 = 2/15`.

The probability that the drawn card is a multiple of 7 is `2/15` (≈ 0.1333).