and a and k are positive constants.[In Section 9.4 we will see that this is a reasonable model for pit).] (a) Find lim, » p(t). (b) Find the rate of spread of the rumor. (c) Graph p for the case a = 10, k = 0.5 with / measured in hours. Use the graph to estimate how long it will take for 80% of the population to hear the rumor.

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