Abag contains 10 red marbles, 15 yellow marbles, 5 green marbles, and 20 blue marbles. five marbles are drawn from the bag. what is the aproximate probability that exactly two of the five are blue?

To determine the probability that exactly two of the five marbles are blue, we will use the rule of multiplication. 

Let event A = the event that the first marble drawn is blue; and let B = the event that the second marble drawn is blue. 
To start, it is given that there are 50 marbles, 20 of them are blue.  Therefore, P(A) = 20/50
After the first selection, there are 49 marbles left, 19 of them are blue. Therefore, P(A|B) = 19/49
Based on the rule of multiplication:P(A ∩ B) = P(A)*P(A|B)P(A ∩ B) =  (20/50) (19/49)P(A ∩ B) = 380/2450P(A ∩ B) = 38/245 or 15.51%

The probability that there will be two blue marbles among the five drawn marbles is 38/245 or 15.51%

We got the 15.51% by dividing 38 by 245. The quotient will be 0.1551. We then multiplied it by 100% resulting to 15.51%

These are the multiples of 15 but what you are probably asking or what are the factors of 15