There are 10 marbles in a bag, and the marbles are either red or blue. eric will randomly choose two marbles from the bag, without replacing the first one. if the probability of both marbles' being red is 2/15 , how many blue marbles are in the bag?
a) 3
b) 4
c) 5
d) 6

The answer is option D = 6

Step-by-step explanation:

Let the number of red marbles be = r

Let the number of blue marbles be = 10-r

But as information about red marbles is given, so solving with respect to red (r)

Solving this we get:

This gives (r-4)=0 and (r+3)=0

r cannot be negative, so r = 4

Red marbles are = 4

Blue marbles are = 10-4 = 6

Hence, there are 6 blue marbles in the bag.

describing distributions is one of the key skills you’ll need to earn a high score on the ap statistics exam. if you need proof of this, just flip through some past exam questions, which can be found at the collegeboard website. you’ll notice that the first free response question is almost always a question requiring you to look at a graph and describe it.

step-by-step explanation: just trying to get points sorry : (