The 6,000 oranges harvested at an orange grove are a combination of valencia and navel oranges. the ratio of valencia oranges to navel oranges is 7 : 5. the owner of the orange grove finds that 1 in every 20 valencia oranges and 1 in every 25 navel oranges are rotten a) what fraction of oranges are not rotten? b) what is the probability that a randomly selected orange is a good orange? c) what is the probability that a randomly selected orange is a rotten valencia?