Hey there!
a) --›initial number = 3750
--›rate = 2.5%
let y be the population t years after 2021
So, y = 3750(1+2.15) ^ t
=> 3750 × 1.0215 ^ t
b) In 2036,
=> t = 2036 - 2021
=> 15
Substitute into the first value
=> 3750 × 1.0215 ^ t
=> 3750 × 1.0215 ^ 15
=> 5159.
Therefore, the population in 2036 would be 5159