The minimum number of cards to be dealt from an arbitrarily shuffled deck of $52$ cards to guarantee that three cards are from same suit is
Can this question be solved by calculating expectation:
Expectation of getting three cards from same deck->
E(x) = 13*(13/52) + 12*(12/51) + 11*(11/50)
= 8.49 => 9 cards
Hence 9 is the answer.
Is it correct?