A bacteria culture begins with 13 bacteria which triple in amount every hour. How many bacteria exist in the culture at the 11th hour?

Question

tkhunny · Answer

How many are there after one hour?

anonymous · Answer

I don't know. The answer choices are  
13,312 

 26,624 

 767,637 

 2,302,911

tkhunny · Answer

I do not believe that.  Read the problem statement again and tell me how many there are after one hour.  Start with 13 and triple it.

anonymous · Answer

13 x 3 = 39 (hr 1)
39 x 3 = 117 (hr 2)
117 x 3 = 351 (hr 3)
351 x 3 = 1053 (hr 4)
1053 x 3 = 3159 (hr 5)
3159 x 3 = 9477 (hr 6)
9477 x 3 = 28431 (hr 7)
28431 x 3 = 85293 (hr 8)
85293 x 3 = 255879 (hr 9)
255879 x 3 = 767637 (hr 10)
767637 x 3 =  2,302,911 (hr 11)

anonymous · Answer

Thank you

anonymous · Answer

Sorry I don't have the technical know how to write that in a usable formula

tkhunny · Answer

t is the number of hours since we started.

$f(t) = 13\cdot 3^{t}$

Find f(11).

anonymous · Answer

That's wrong for future references

tkhunny · Answer

Actually, that's exactly correct, in case you need an immediate reference.  Perhaps, sometime in the future, arithmetic will work differently.  For now, you probably should go with how it works, today.