The numbers can be arranged in 720 ways.
There are 6 people possible for the first position; 5 for the second; 4 for the third; etc. This gives us 6! = 720.
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.
Answer: I do not understand the options you gave but but cos30º is equal to 
/2 which is 0.86602540378.
If you round up the 27.64 to 28 and then multiply it bye 3 it eaquals 84
Angle ab would be the correct answer
