Perhaps the most common error in ranking poker hands involves confusing the order of a straight and a flush. if 5 cards are drawn from the deck at random (without replacement) to form a hand, which hand is more likely: a straight or a flush?

With a flush you just have to match the suit (spade diamond hearts clubs) they can be any card but in that suit. 

A straight you have to have 5 cards in order (12345) in any suit. 

Excluding a royal straight or flush (because the probability is lower) you have a higher chance of getting a straight (.3925% or 251:1 odds) than you do a flush (.1965% or 5085:1 odds). 

Hopefully this helps =)