I'm studying for a high school test on probability and came across this problem:
Jessica bought a crate of apples from a farm. The farmer told her that when randomly grabbing an apple from the crate, there's a 0.05 probability that it is rotten.
The question: If Jessica were to randomly grab 5 apples from the crate, what is the probability that exactly 2 would be rotten?
It doesn't say how many apples are in the crate(hence my confusion) so I simply assume that there are 100 apples for example. My calculation:
95C3 * 5C2 / 100C5 which equals to about 0.018. It says here that the correct answer is 0.021. Where did I go wrong? Any help would be awesome.