A bag contains ten marbles of equal size and weight. One marble is blue, one marble is white, three are yellow, and five marbles are red. A marble is taken from the bag two times. Each time a marble is taken out, it is not replaced. What is the probability of picking a red marble and picking a red marble?
A) 1/4

B) 2/9

C) 9/10

D) 7/45

B) 2/9

Step-by-step explanation:

First, the probability of picking a red marble is 5/10, which is the same as 1/2. This is because there are 5 marbles in the bag that are red out of the 10 total marbles. Then, because we don't replace the marble, there are now 9 total marbles, with 1 blue, 1 white, 3 yellow, and 4 red. Now the probability of picking a red marble is 4/9.

Multiplying these two probabilities together gives you the probability of picking 2 red marbles in a row, which is 1/2 * 4/9 which is equal to 4/18, or 2/9 when simplified.

85.560%

step-by-step explanation:

conditional probability is defined as:

p(a|b) = p(a∩b) / p(b)

in other words, the probability that a occurs, given that b has occurred = the probability that both a and b occur / the probability that b occurs.

in this example:

p(turns 64 | turns 44) = p(turns 64 & turns 44) / p(turns 44).

if someone turns 64, they must have already turned 44, so:

p(turns 64 | turns 44) = p(turns 64) / p(turns 44)

on page 42, we see that of the original 100,000, 94944 turn 44, and 81234 turn 64.   therefore:

p(turns 64 | turns 44) = 81234 / 94944

p(turns 64 | turns 44) = 0.85560

i’m sorry but i don’t know sorry