Need help with this math question

Question

A certain bacteria will triple in population every 3.5 hours. A certain test tube contains 50 bacteria. Find an exponential function that models the situation. How many bacteria will be in the test tube at 7 hours later? When will the bacteria reach a population of 4050? How many bacteria will be in the test tube at 9 hours later?

Answer 1

A(t) = A₀ (3)^t/3.5

t = hours

A₀ = initial number = 50

A(t) = 50 (3)^t/3.5

A(7) = 50 (3)^7/3.5 = ?

Time to reach 4050:

4050 = 50 (3)^T/3.5

Solve for T using the properties of logs. For the amount 9 hours later, reset A₀ to 4050, and compute

A(9) = 4050 (3)^9/3.5 = ?

You should be able to finish from here.