Question

There are 10 yellow, 6 green, 9 orange, and 5 red cards in a stack of cards turned facedown. Once a card is selected, it is not replaced. Find each probability.
P(two yellow cards)
P(a yellow card and then a green card)
P(two cards that are not orange)
P(two cards that are neither red nor green)
P(two green cards)
P(a red card and then an orange card)

Answer 1

10 yellow cards over 30 = 10/30
second selection : 9 yellow cards over 29 = 9/29

10/30 * 9/29 = 1/3 * 9 /29 = 3/29 = 0.1034 = 10.34%

Answer 2

P( 2 yelloes ) =  10/30 * 9/29 =  = 90 / 870 = 9/87 = 3/29 Anser

P(Y then G) = 10/30 * 6/29 = 2/29  Answer

P(2 cards not orange) =  21/30 * 20/29 = 14/29

P(2 cards neither G nor R) =  19/30 * 18/29 =  57/145

P(2 G) = 6/30 * 5/29 = 1/29

P( R then O) =   5/30 * 9/29  =  3/58