Question

you have 60 cards, half are red and half are black.

what is The probability

A) to get the first two red

B ) the first three red

C) the first two red and the third is black

Answer 1

(A)

There is 60 cards in a deck half of them are red and the other half is black.

If you try to pick one of the red cards there is a half chance of getting it, 1/2.

The second card you want to pick is a red (29 reds:half deck>30-1= 29) out of the 30 red cards left.

Math part:

P(RR):

(B)

same like A,

if u try to pick the third red card (28 reds) out of 30 reds left.

Math part:

P(RRR):

(C)

FOR getting two red and one black:

We have three possible sequences of cards that satisfy your conditions (two RED, one BLACK): RRB, RBR and BRR. Let P(BRR),P(RRB),P(RBR)

BUT your question consists of first two red and last one as BLACK i.e., P(RRB):

When we draw the first card, there are 30 RED cards and 60 cards total, so there is a

chance that this card is RED. If the first card is RED, there are 29 RED cards out of 59 total when we draw the second card, so there is a

chance it is RED. If the first two cards were both RED, then there are 30 red cards out of 58 total when we draw the third card, so there is a

chance it is BLACK.

Thus P(RRB):

.