This week, Maria ate 60%, or 420 grams, of a jumbo box of cereal. How much cereal was in the whole box?
How would you begin to set up this problem?

Please hurry

X+ y = k 2x + 3y = k + 1 the point of intersection of the lines has an x-coordinate of a.2k + 1 b.-2k + 1 c.2k - 1

Find the value of a. the diagram is not to scale. a quadrilateral is drawn. the upper and lower sides are parallel. the interior angle in the upper left corner is labeled a degrees. the angle in the upper right corner is labeled 113 degrees. the angle in the lower right corner is labeled b degrees. the angle in the lower left corner is labeled 36 degrees. a. 36 b. 144 c. 54 d. 126

Asap! i'm not good math and i'm lost.