CAPE Pure Mathematics Unit 2 · May/June 2017 · Paper 1 · Question Q8

The number of bacteria present in a culture is modelled by y = y_0 e^{kt}, where k > 0, y is the population after t hours, and y_0 is the initial population. The rate of growth, c, when t = 5 is given by

1. (A)c = e^{5k}
2. (B)c = ke^5
3. (C)c = 5e^{5k}
4. (D)c = ky_0 e^{5k}