Question

box contains 30 cards from 1 to 30 card is drawn random from the box find the probability that (1) it is a divisible by 2or 5 (2) a prime number

Answer 1

total no of outcomes= 30
1) favourable outcomes = 21
probability= 21/30 = 7/10
2) favourable outcomes= 10
probability = 10/30 = 1/3

Answer 2

1) Probability that the card has number divisible by 2 or 5 = 3/5

2) Probability that the card has a prime number = 1/3

The total number of cards in the box = 30

The total prime numbers from 1 to 30 = 10 {2, 3, 5, 7, 11, 13, 17, 19, 23, 29}

Total numbers between 1 to 30 that are divisible by 2 or 5 = 18

The probability of getting a number divisible by 2 or 5 = 18/30 = 3/5

The probability of getting a prime number = 10/30 = 1/3