20 marbles in a bag. 4 are red, 5 are blue, 5 are black, 4 are white and 2 are yellow. What is the probability that he pulls out a red marble?

1/5

Step-by-step explanation:

Probability calculates the likelihood of an event occurring. The likelihood of the event occurring lies between 0 and 1. It is zero if the event does not occur and 1 if the event occurs.

For example, the probability that it would rain on Friday is between o and 1. If it rains, a value of one is attached to the event. If it doesn't a value of zero is attached to the event.

probability that he pulls out a red marble = number of red marbles / total number of marbles

= 4/20 = 1/5

-22

times both sides by 2, times () by 8, add alile terms, move terms, add alike and caculate divide both sides by 3