Hello so can someone help me with this problem. My teacher doesn't explain it very well </3​

Simplify a7/a4 a) 1/a3 b)-a/a2 c)a4/a3 d)a3

How do i take any fraction and make it into a decimal or percentage?

Fracisco's game involves 3 green, 2 yellow, 4 red, and 3 black marbles. if he randomly draws three marbles from the bag, without replacement, what is the probability that he will draw yellow, and then red, and then black? a)1/192 b)1/72 c)3/220 d)1/55