I think this mean that in whatever equation you have, w must be representing -3. Not sure though :)
1. Your question tells that the percentage of the red marble in the bag is 25%. So if a child chooses 4 marbles, the probability that he could get 3 red marbles is A.0.047
2.In your question the supplier has a stock of parakeets were 10% is blue, so the chance of the supplier to deliver 1 blue parakeet out of 3 is letter B.0.243
16dividedby3 which is 5 and 1 third or 5 remainder 1