A box contains 5 green, 4 yellow and 3 white marbles, 3 marbles are drawn at random. What is the probability that they are not of the same colour?
Select the correct option.
A) 13⁄44  B) 41⁄44  C) 13⁄55  D) 52⁄55  E) None of these
Total no. of ways of drawing 3 marbles   = 12C3 = 12×11×10/1×2×3=220   Total no. of ways of drawing marbles, which are of same colour = 5C3 + 4C3 + 3C3 = 10 + 4 + 1= 
<gadget id="calculator">10 + 4 + 1</gadget>
<output>15</output>
15   \Probability of same colour= 15⁄220 = 3⁄44   \ Probability of not same colour = 1 - 3⁄44 =   Answer 41⁄44
<result>B</result>
A box contains 5 green, 4 yellow and 3 white marbles, 3 marbles are drawn at random. What is the probability that they are not of the same colour?