Question

All the heart cards are taken out from a pack of playing cards. From these cards, cards are drawn one by one without replacement till the ace of hearts comes. The probability that ace comes in the 4th draw is
A. `(1)/(13)`
B. `(12)/(13)`
C. `(4)/(13)`
D. none of these

Answer 1

Correct Answer - A
Clearly,
Required probability
=Probability of getting 3 non-ace cards in first three draws and getting an ace in fourth draw
`=(.^(12)C_(3))/(.^(13)C_(3))xx(1)/(10)=(1)/(13)`