Exponential growth function is given by f(t) = A(1 + k%)^t; where A is the initial value, k is the growth rate and t is the time period.
Therefore, the required function is
f(t) = 120,000(1 + 0.012)^t = 120,000(1.012)^t
After 15 years, the new population is 120,000(1.012)^15 = 120,000 x 1.1959 = 143,512
