Question

In a bacteria culture the number of bacteria doubles after every minute. If a dish is full of bacteria exactly after 10 minutes when was it half full? ​

Answer 1

Answer:  The dish was half full after 9 minutes.

Step-by-step explanation: Given that in a bacteria culture, the number of bacteria doubles after every minute and a dish is full of bacteria exactly after 10 minutes.

We are to find the numbers of minutes after which the dish was half full.

Let x minutes be the required time after which the dish was half full.

Then, according to the given information, we have

$x+1=10\\\\\Rightarrow x=10-1\\\\\Rightarrow x=9.$

Thus, the dish was half full after 9 minutes.