📐 Mathematics · Probability (Class 11) · JEE

A number is chosen at random from 1 to 20. The probability it is divisible by 3 or 5 is:

Answer: 9/20.

Correct answer: A. 9/20

Explanation: Divisible by 3: 6 numbers, by 5: 4, by 15: 1, so 6 + 4 − 1 = 9 out of 20.

Concept context

Random experiments, sample space, events, and the axiomatic approach to probability