Question

Suppose 10 cards numbered I to lo are placed in a box and shuffed and one card is drawn at random. 

(i) If A is the event that the number on the card is even, then write A. 

(ii) If B is the event that the number on the card is more than 3, Find P(A/B).

Answer 1

A = {2,4,6,8,10} B = {4, 5, 6, 7, 8, 9, 10}

A ∩ B = {4,6,8,10}

P(A/B) = \(P(A / B)=\frac{P(A \cap B)}{P(B)}=\frac{\frac{4}{10}}{\frac{7}{10}}=\frac{4}{7}\)