A drawer contains 10 blue pens, 10 black pens, and 10 red pens. Without looking. Mr. Lopez is going to take one pen from the drawer, use it, and then put it back into the drawer. Then he is going to take another pen from the drawer to use. What is the probability of Mr. Lopez taking a red pen first and then taking a blue pen?

1/9

Step-by-step explanation:

There are 30 pens in total, 1/3 of the pens are each the following colours: blue; black; red.

This will result in a one in three chance of picking up a red pen. As Mr.Lopez puts the pen back, the fractions stay the same as it's the same possibility both times.

As it's again a one in three chance, we just have to multiply it for the possibility of him picking a blue pen, which is 1/3.

1/3 * 1/3 = 1/9

median is the value separating the higher half of a data sample, a population or probablity distribution from the lower half.

step-by-step explanation:

say you have 3,8,7,3,1,9,8 order them from lowest to highest

if orderd it would be 1,3,3,7,8,8,9 now you take away from the lowest and the highest until you end up in the middle.

so you would remove the 1 and 9 leaving you with 5 digits remaining

when you've reached the middle that would be your answer so in this case the answer is 7

if there were two numbers left say 7 and 5 you'd and them together so 12 then divide by 2 witch would equal 6 so the answer would be 6

good luck on that project hoped i you at all