Question

If a spoon has 69,789,200 of a certain microbe on its surface and you treat it with a germicide that has a value of 10 minutes, how many minutes will it take to sterilize the spoon?

Answer 1

Solution

The value of germicide is 10 minutes. It means, the germicide will reduce the microbial population to 10 % of the initial value within this 10 minute.

Now, we have initial value of 69,789,200 microbes.

In the first 10 minutes, it will reduce the microbial pouplation to 69,789,20

In the next 10 minute, the microbial population reduced to 69,789,2

Like wise

1st 10 minute - 6978920

2nd 10 minute - 697892

3rd 10 minute- 69789.2

4th 10 minute- 6978.92

5th 10 minute - 697.892

6th 10 minute- 69.7892

7th 10 minute - 6.97892

8th 10 minute- 0.697892

The spoon can be said sterilized in the 80th minute of sterilization by the germicide.