Someone help me on this question
it's two step inequalities
i forgot how to do 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

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle

What is the absolute value of -100000000000000?