A bag contains 25 cards, numbered through 1 to 25. A card is drawn at random. What is the probability that the number on the card drawn is :
(a) a multiple of 5
(b) a perfect square
(c) a prime number ?
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Total number of outcomes = 25
(a) Number of multiples of 5 between 1 to 25 = 5 (5, 10, 15, 20, 25).
P(that number on card is a multiples of 5)
= $\frac{\text{No. of multiples of 5}}{\text{Total number of outcomes}} = \frac{5}{25} = \frac{1}{5}$.
Hence, the required probability is $\frac{1}{5}$.
(b) Number of perfect squares between 1 to 25 = 5 (1, 4, 9, 16, 25).
P(that number on card is a perfect square)
= $\frac{\text{No. of perfect squares}}{\text{Total number of outcomes}} = \frac{5}{25} = \frac{1}{5}$.
Hence, the required probability is $\frac{1}{5}$.
(c) Number of prime numbers between 1 to 25 = 9 (2, 3, 5, 7, 11, 13, 17, 19, 23).
P(that number is a prime number)
= $\frac{\text{No. of prime numbers}}{\text{Total number of outcomes}} = \frac{9}{25}$.
Hence, the required probability is $\frac{9}{25}$.