What percent of the grid is shaded?

According to the number line, what is the distance between points a and b? v ++ + + + + -16 -14 -12 -10 -8 + 6 + 4 + -2 + 0 + 2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 o6 units o 7 units 12 units o 14 units

The general form of the quetion of a circle is ax^2+by^2+cx+dy+e=0 where a=b=0 if the circle has a radius of three units and the center lies on the y axis which set of values of a, b, c, d, and e might correspond to the circle

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?