Two cards are drawn successively from a well-shuffled ordinary deck of 52-playing cards without replacement and is noted that the second card is a king. Find the probability of the event 'first card is also a king'

Explanation

This is a squestion of bayes theorem

There are 2 possibilities either first card is king or not.

Let A be the event 1st card is king, B second card is king and C 1st card is not a king.

`P(A/B)=(P(B/A)P(A))/(P(B/A)P(A)+P(B/C)P(C)`

substituting values we get=>`P(A/B)=(3/51xx4/52)/(4/52xx3/51+4/51xx48/52)=1/17`