Question

Thirty identical cards are marked with numbers 1 to 30. If one card is drawn at random, find the probability that it is a multiple of 3 and 5. 

Answer 1

There are 30 cards from which one card is drawn. 

Total number of elementary events = n(S) = 30 

From numbers 1 to 30, there are 2 numbers which are multiple of 3 and 5 i.e. {15, 30}

Favourable number of events = n(E) = 2 

Probability of selecting a card with a multiple of 3 and 5 = `(n(E))/(n(S)) = 2/30 = 1/15`