Question

1) Roberto has been studying a type of bacteria that doubles every month. Originally, there were 3 bacterial cells. He wants to know how many there will be after 43 months. Which equation should he use?

A) a43 = 3(2)(43)

B) a43 = 3(2)^43

C)a43 = 3(2)(43 − 1)

D) a43 = 3(2)^43 − 1


2)The population of a type of local frog can be found using an infinite geometric series where a1 = 84 and the common ratio is one fifth. Find the sum of this infinite series that will be the upper limit of this population.

A)87

B)105

C)425

D)The series is divergent.

Answer 1

For number I am not 100% sure but I think its A.

The second one you use the formula
a/(1-r)

where a is the first number and r is the ratio.
so a here is 84 and r = 1/5

I hope this helped.

Answer 2

Thanks!

Answer 3

Was the first answer correct?