There are 10 red cards, 20 blue cars and 15 yellow cards. What is the probability of picking a red card after picking a yellow card or blue card?
+9665 P(picking a red card after picking a yellow card or blue card)
= 7/9 x 5/22
= \(\dfrac{35}{198}\)
Ooh this is not quite possible actually...... I thought this probability would be large! :D
+129840 I get a little different result from Max, but since I'm not great at probability, maybe mine is more of an "educated" guess.....
If we have picked a blue or yellow card on the first draw, then the chances of selecting a blue or yellow card on the second draw = 34/44
Then....the chances of NOT selecting a blue or yellow card on the second draw = the probability of selecting a red card on the second draw = 1 - 34/44 = 10/44 = 5/22
Can someone else check this ?????
+33653 The only way of not picking a red card after picking a blue or yellow card is to pick all the red cards first. The probability of doing this is q = 10!*35!/45! i.e. (10/45)*(9/44)*...*(1/36)
Hence, the probability of picking a red card after picking a blue or yellow card is p = 1 - q
I've assumed the question intends all the cards to be picked; that it doesn't just refer to the 1st and 2nd cards picked.
