word problem

Question

A sample contains 130 bacteria. This type of bacteria quadruples every hour. Write an equation that relates the number of hours, n. Then find the number of bateria after 5 hours.

Answer 1

I'm guess that you want an equation that relates the number of bacteria to the number of hours, right?

 

If so, then it would be B = 130 * 4ⁿ

 

where B is the number of bacteria and n is the number of hours.

 

Substitute 5 for n to get the number after 5 hours:

 

B = 130 * 4⁵ = 130 * 1024 = 133120