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Question
Cards numbered from 11 to 60 are kept in a box. If a card is drawn at random from the box, find the probability that the number on the drawn card isa prime number less than 20
Solution
The cards are numbered from 11 to 60.
∴ Total number of outcomes = 60 − 10 = 50
Prime numbers less than 20 from 11 to 60 are 11, 13, 17 and 19.
So, the favourable number of outcomes are 4.
∴ P(number on the drawn card is a prime number less than 20) =\[\frac{\text{ Favourable number of outcomes }}{\text{ Total number of outcomes }} = \frac{4}{50} = \frac{2}{25}\]
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