You draw a card at random from a deck that contains 333 black cards and 777 red cards. What is \text{P(draw a black card})P(draw a black card)start text, P, left parenthesis, d, r, a, w, space, a, space, b, l, a, c, k, space, c, a, r, d, end text, right parenthesis? If necessary, round your answer to 222 decimal places.

The probability of picking a black card at random, from a deck with 3 black cards and 7 red ones is 0.3.

Step-by-step explanation:

We will assume that we have 3 black cards and 7 black cards, for a total of 10 cards. Since we are taking one card at random, we can assume that each card is equally likely to be drawn. We have the following event A: The drawn card is a black. We will find the probability of A as counting the number of outcomes that make A to occur and divide it by the total number of possibilities. We are drawing one card, so we have 10 possibilities to be picked. Out of those 10, only 3 cards are black, hence we have 3 possibilites of picking a black card.

Then,

P(A) = 3/10 = 0.3.

b) 1/3 * 1/5

step-by-step explanation:

each smallest part is 1/15 since the written one is 1/5 and it's divided by 3 equal parts. (1/5 )/3 = 1/15 = 1/3 * 1/5