Question
Mathematics Question on permutations and combinations
Find the number of ways of choosing 4 cards from a pack of 52 playing cards when cards are of the same colour.
A
29900
B
29925
C
29910
D
29920
Answer
29900
Explanation
Solution
4 red cards can be selected out of 26 red cards in 26C4 ways. 4 black cards can be selected out of 26 black cards in 26C4 ways. Therefore, the required number of ways =26C4+26C4 = 2×4!22!26!=29900.