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Question
A box contains 20 cards numbered from 1 to 20. A card is drawn at random from the box. Find the probability that the number on the drawn card is a prime number.
Solution
Total number of cards = 20
Prime numbers are 2, 3, 5, 7, 11, 13, 17 and 19.
Total favourable number of cards = 8
Probability that the number on the drawn card is a prime number = `"Total favourable number of cards"/"Total number of cards"=8/20=2/5`
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