7/10 of a farmers crop is corn. 2/3 is sold for biofuel. what percent of total crop was used for fuel?

Two streets intersect at a 30- degree angle. at the intersection, the are four crosswalks formed that are the same length. what type of quadrilateral is formed by the crosswalks?

The sum of the speeds of two trains is 720.2 mph. if the speed of the first train is 7.8 mph faster than the second train, find the speeds of each.

Suppose the equation ||x-a|-b|=2008 has 3 distinct real roots and a not =0. find the value of b.