I really need help on this

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

An internet company charges $8.95 per month for the first 3 months that it hosts your web site. then the company charges $11.95 per month for web hosting. how much money, in dollars, will the company charge for 8 months of web hosting?

Tan198=asin164=? how to solve this? ?