In a box, there are 10 red, 6 blue and 5 green balls. One ball is picked up randomly. What is the probability that it is neither red nor green?
Choose the correct choice from the following answers.
A) 4/51 B) 10/21 C) 7/12 D) 11/31 E) 13/17
Total number of balls = 10+6+5= 
<gadget id="calculator">10+6+5</gadget>
<output>21</output>
21   E= event that the ball drawn is neither red nor green   = event that the ball drawn is red   n(E) = 10   P(E) = 10/21   Answer is 10/21
<result>B</result>
In a box, there are 10 red, 6 blue and 5 green balls. One ball is picked up randomly. What is the probability that it is neither red nor green?