Question

5. The bacteria in a culture grows by 5% in the first hour, decreases by 5% in the second hour and again
increases by 5% in the third hour. If the original count of bacteria in a sample is 5,000, find the bacteria
count at the end of 3 hours.
​

Answer 1

Answer:  The number of the bacteria at the onset=10000.

Step-by-step explanation:

We know that Final count = initial count±((initial count)×100 time×rate​).

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

10000+(10000×10010​)=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−(11000×10010​)=9900.

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

∴ In the third hour, the number of bacteria is

9900+(9900×10010​)=10890.

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

Answer 2

Step-by-step explanation:

according to the question

1hour=5000*(1+5/100)

=250+5000=5250

2hour=5250*(1-5/100)

=262.5+5250=4987.5

3hour=4987.5*(1+5/100)

=49.875+4987.5

5037.375 is written as 5237ans