Given the arithmetic sequence where a1=6 and a5=-6 , what is a3

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

Anyone know these questions? i need ,.

Of the 304 people who attended a school play, 5/8 were students. how many of the people who attended were students.