Question

At the start of an experiment there are 20000 bacteria.
The number of bacteria increases at a rate of 30% per hour.
(a) Work out the number of bacteria after 4 hours.
(b) After how many whole hours, from the start of the experiment, will the number of bacteria be greater
than one million?

Answer 1

Step-by-step explanation:

bacteria increase 30 percent per hour so

30 percent of 20000

30/100x20000

=6000 bacteria increase after 1 hour so in 4 hour

6000x4

24000 in 4 hour total bacteria after 4 hrs =20000+24000 =44000

one million =1000000

Answer 2

Answer:

(a) 57122

(b) 15

Step-by-step explanation:

(a) Use the Compound Interest formula: A = P(1+r/100)^t

So, it would be:

A = 20000(1+30/100)^4

A = 57122

(b) Same formula would apply so:

A = 20000(1+30/100)^x

Finding x would be a long a tough process so instead we can hit and trial the to find the value of x.

Therefore, the value of x will be 15 as it is the first number in which A > 1000000