Please help me im lost

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

Which of the following vectors are orthogonal to (2,1)? check all that apply

The letters g e o r g i a are placed in a bag . if you picked a card and knew it was a vowel , what is the probability that it is an a ?