Arturo O. answered 05/19/20
Experienced Physics Teacher for Physics Tutoring
This is an example of exponential growth. At the end of each month, you will have 1.02 times the number you had at the start of the month.
p(n) = p0 (1.02)n
p0 = initial population = 821
n = number of months elapsed from when the population was 821
p(n) = 821 (1.02)n
Plug into the equation the number of months (n) in half a year, 2 years, and 10 years, and evaluate.