math and probability

Question

I have a drawer with 5 blue markers and 10 black markers.

A. I randomly reach in and grab 3 to bring to class. What is the probability they are all blue?

B. For another class, every school day for a week (5 days) I randomly grab a single marker from the drawer. What is the probability the marker I grab is black every day? Assume I put the marker back in the drawer after each class.

Answer 1

P(all 3 blue)= (1/3)^3= 1/27?

or

5/15 x 4/14 x 3/13 = 1/3 x 2/7 x 3/13 = 6/273

1/27= 6/142 a/most twice 6/273

2nd looks correct 6/273