Question

Grace placed 3 strands bacteria in a petri dish. The bacteria strands triple every hour. Write a formula to

represent at the nth hour. then use the formula determine how many strands of bacteria are represent
at 4 hours.

Answer 1

81 is THE ANSWER

Explanation:

Answer 2

a) The growth of bacteria at nth hour is :
`3^(n)`

b) At the end of the fourth hour, there are 81 stands of the bacteria

present.

Explanation:

The number of initial bacteria in the dish = 3 strands

Rate at which bacteria multiply = 3 times every hour

So, the general form which represents the growth

As it multiplies three times every hour, so at nth hour:

The growth of bacteria at nth hour is :
`3^(n)`

Now, at n = 4, the growth of the bacteria is
`3^(4)`

= 3 x 3 x 3 x 3

⇒
`3^(4)` = 81

So, at the end of the fourth hour, there are 81 stands of the bacteria present.