A box held 20 blue marbles and 30 red marbles. One marble is drawn at random. What is the probability that the marble is red?
Choose the correct choice from the following:  A) 1/4  B) 2/5  C) 3/5  D) 3/4  E) None of these
Explanation:   Total cases = 20 + 30= 
<gadget id="calculator">20 + 30</gadget>
<output>50</output>
50   Favourable cases= 30   So probability = 30/50 = 3/5   Answer: 3/5
<result>C</result>
A box held 20 blue marbles and 30 red marbles. One marble is drawn at random. What is the probability that the marble is red?