There is a total of 90 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 1/6 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 correct choice from the following answers:
A) 3 / 5
B) 7 / 15
C) 11 / 15
D) 19 / 30
E) 23 / 30

Rationale: "p ( red or blue ) = 1 - p ( white ) - p ( green ) = 30 / 30 - 5 / 30 - 6 / 30 = 19 / 30 the answer is d ."
Answer: D