Two reservoirs are located upstream of a town; the water is held back by two dams A and B. Darn B is 40 m high (see Fig. 1a). During a strong earthquake ground motion, dam A will suffer damage and water will ow downstream into the lower water reservoir. Depending on the amount of water in the upper reservoir when such an earthquake occru's, the lower reservoir water may or may not overow dam B. Suppose that the water level at reservoir B at the start of an earthquake is either 25 m or' 35 m, as shown in Fig. 1b; and the increase in the elevation of the water level in dam B caused by the additional water from reservoir A is a continuous random variable with the probability density function given in Fig. lo. (a) Determine the value of parameter \"a\" if Fig. 1c. (b) What is the probability of overow at dam B during a strong earthquake ground motion? (c) If there were no overow at dam B during an earthquake, what is the probability that the original water level in reservoir B was 25 m? Figure 1a him I - rm ill In. um II m I 1H Figure I!) Figure 1c