From the statement of the problem, we know that:
• the initial population of bacteria in a colony is N_0 = 500,
,
• the number of bacteria doubles every △t = 260 min.
We can model the population of bacterias in the colony by the exponential function:

After a time t = 520 min, the population will be:

Answer
After 520 minutes, the population will be 2000 bacterias.