Can someone really help me with this? I attached a screen shot!

Np4=12np2 with clear explanation.

Abag contains 4 red, 7 blue and 5 yellow marbles. event a is defined as drawing a yellow marble on the first draw and event b is defined as drawing a blue marble on the second draw. if two marbles are drawn from the bag, one after the other and not replaced, what is p(b|a) expressed in simplest form? a. 7/16 b. 7/15 c. 14/16 d. 14/15

Round each decimal to the nearest thousandth. a. 5.39562 b. 0.12345 c. 5634 d. 18.93763