The probability of an event P happening is \(\frac{1}{5}\) and that of event Q is \(\frac{1}{4}\). If the events are independent, what is the probability that neither of them happens?
The radii of the base of two cylindrical tins, P and Q are r and 2r respectively. If the water level in p is 10cm high, what would be the height of the same quantity of water in Q?
