(b) Emily, Rebecca and Caroline are training for a marathon. They need to train by running several times a week over a six-week period. The probability that on a particular day Emily chooses to run is 0.45, for Rebecca this probability is 0.25, and for Caroline this probability is 0.3. What is the probability that all three will choose to run on the same day? State any important assumption that you make in order to calculate this probability. [3]