I believe there is a 1/20 chance that Mrs. Galvan will pick a black pin. Since there are 20 pens, each pen has an equal chance of getting picked. For example, you have 2 pens and one of them is blue. The chance of me getting the blue pen is 1/2 or a 50% chance. So your answer will be 1/20 chance.
-2/2 = -1/1 = -1
Therefore, the absolute value of -2/2 is -1.
