There is a total of 100 marbles in a box, each of which is red, green, blue, or white. If one marble is drawn from the box at random, the probability that it will be white is 1/4 and the probability that it will be green is 1/5. What is the probability that the marble will be either red or blue? Choose the most appropriate option.
A) 2/3	B) 3/5	C) 7/10	D) 9/20	E) 11/20
P(red or blue) = 1 - P(white) - P(green) = 20/20 -5/20 - 4/20 = 11/20   The answer is 11/20.
<result>E</result>
There is a total of 100 marbles in a box, each of which is red, green, blue, or white. If one marble is drawn from the box at random, the probability that it will be white is 1/4 and the probability that it will be green is 1/5. What is the probability that the marble will be either red or blue?