Out of first 20 natural numbers, one number is selected at random. The probability that it is either an even number or a prime number is_____________?
Q1. Out of first 20 natural numbers, one number is selected at random. The probability that it is either an even number or a prime number is_____________?
Answer: 17/20
Explanation: Even numbers from 1–20: 10; primes from 1–20: 8; union = 10+8−1 (for 2) = 17; probability = 17/20.