If the population of the bacteria doubles every 24 hours, then after 1 day (24 hours), the population will be twice as large as it was at the start. After 2 days (48 hours), the population will be twice as large again, or 4 times the starting population. Similarly, after 3 days (72 hours), the population will be 8 times the starting population, after 4 days (96 hours), the population will be 16 times the starting population, and after 5 days (120 hours), the population will be 32 times the starting population.
Therefore, the population of the bacteria after 5 days will be 32 times as great as the population was at the start