Subject: mathqa
Question: a certain bag contains 100 balls â € ” 50 white , 25 green , 10 yellow , 7 red , and 8 purple . if a ball is to be chosen at random , what is the probability that the ball will be neither red nor purple ?
Option: 
A: 0.8
B: 0.5
C: 0.6
D: 0.85
Answer: D