Before 3 hours, there are 10,000 cells.
After 3 hours, there are 500,000 cells.
Well, 500,000 - 10,000 = 490,000
So for every 3 hours, there are 490,000 cells present.
In one day, there are 24 hours. But we don't have exactly that 24 hours in our given! So we are going to divide 24 by 3.
24/3 = 8.
Now, we knew that for every 24 hours, there are 8 of 3 hours present on it.
Now, we knew that for every 3 hours, there are 490,000 cells present.
8 (490,000)
3,920,000
So therefore,
there can be 3,920,000 cells present on the bacteria-s