Question

3. The bacteria in a culture grows by 10% in the first hour, decreases by 10% in the second hour and again in
by 10% in the third hour. If the count of bacteria in the sample is 121000000, what will be the count of
after 3 years?​

Answer 1

Answer:

10890

Step-by-step explanation:

The number of the bactera at the onset=10000.

We know that Final count = initial count ± $((initialcount) \times \frac{time\times rate}{100}$

∴ In the first hour, the number increases by 10%,so total number of count becomes

10000+(10000×  100

/10  )=11000.

In the second hour, the number decreases by 10%

So the rate is negative.

∴ In the second hour, the number of bacteria is

11000−(11000×  100

/10

)=9900.

In the third hour the number of bacteria increases by 10%

∴ In the third hour, the number of bacteria is

9900+(9900×  100

/10  )=10890.

So, at the end of 3hours  the number of bacteria is 10890.