Question

don't know how to do this please help


A bacteria culture begins with 13 bacteria which triple in amount at the end of every hour. How many bacteria exist in the culture at the end of the 10th hour?

13,312
26,624
767,637
2,302,911

Answer 1

initially,no. is 13
then it becomes 13*3
then (13*3)*3
.
.
.
10 times
so you have a GP like this: 13, (13*3) , (13*3)*3 .....
here a=13
r=3
you need to find sum of this Gp for 10 terms
sum = a(r^n -1)/(r-1)
just make these substitutions
hope this helps.

Answer 2

= 13 * (3) ^10
= ...

Answer 3

@kerber123 can you finish it up?

Answer 4

767,637?

Answer 5

:)

Answer 6

thanks again

Answer 7

again ??

Answer 8

ohh,,am sorry,,i misread the ques..really sorry..

Answer 9

@shubhamsrg It just proves that your thought so complicated than mine :)

Answer 10

i'll take that as a compliment!! lol..

Answer 11

I honestly mean it ;)