Two cards are drawn successively with replacement from a well shuffled deck of 52 cards. Let denote the random variable of number of aces obtained in the two drawn cards. Then, equals
- A.
- B.
- C.
- D.
Show answer and solution
Correct option: A
Solution
P(ace) = 4/52 = 1/13, P(no ace) = 12/13.
P(X=1) = 2·(1/13)·(12/13) = 24/169.
P(X=2) = (1/13)² = 1/169.
Sum = 24/169 + 1/169 = 25/169.
P(X=1) = 2·(1/13)·(12/13) = 24/169.
P(X=2) = (1/13)² = 1/169.
Sum = 24/169 + 1/169 = 25/169.
[JEE Main 2019 · 9 Jan · Shift I]