You have a bag of chocolate candy. ten of them are red, 7 are brown, 12 are green, and 9 are blue. what is the probability that you pick a red candy, given that you have already picked a red candy and have not replaced it?

9/37  is the correct answer.

                           

Since the triangle formed is right triangle, the angle between the floor and the table is 90 degrees. The sum of the angles of a triangle is 180 degrees. We already have the measure of the two angles. Therefore, the measure of the third angle is:
180 - 90 - 12 = 78 degrees