A bag contains 20 tickets, numbered from 1 to 20. Two tickets are drawn without replacement. What is the probability that the first ticket has an even number and the second an odd number.

Explanation

A= in 1st draw An even number


B= in 2nd draw An odd number



`P(A)=frac{10}{20}=frac{1}{2} `

`
P(B / A)=frac{10}{19}`

`

therefore P(A cap B)=P(A) times P(B / A)=frac{1}{2} times frac{10}{19}=frac{5}{19}`