Question

Brett has been studying a type of bacteria that doubles every month. Originally, there were 5 bacterial cells. He wants to know how many there will be after 42 months. Which equation should he use?

Answer 1

5^42

Answer 2

A a42 = 5(2)42 - 1
B a42 = 5(2)(42)
C a42 = 5(2)42
D a42 = 5(2)(42 - 1)

Answer 3

@camerondoherty

Answer 4

@ganeshie8

Answer 5

whats the nth term formula for geometric sequence ?

Answer 6

is that the An=a1+(n-1)d?

Answer 7

thats for arithmetic sequence,
not geometric

Answer 8

thats the only formula my teacher gave me

Answer 9

\[A _{n}=A _{1} \times r ^{n-1}\] I think...

Answer 10

yes thats the formula we need to use here :)

Answer 11

Just a hunch i think a = 5

Answer 12

n=42

Answer 13

yep!

Answer 14

then whats the answer..

Answer 15

Well look at the equation and look at your options. If a=5 and n=42 which one is it?

Answer 16

B?

Answer 17

Not quite

Answer 18

D

Answer 19

look at the equation i showed you again

Answer 20

its A

Answer 21

Yep!