Strategic Problem?

[thunderfury]

It goes something like this:

Tillie the tuna is giving her first concert. The underwater amphitheater is full and waiting for Tillie, Sharleen Shark, and the Fluke Wellington Orchestra. The concert will end with the choir of Angelfish. Molly Marlin is behind the curtain, peeking out at the audience, as Tillie begins singing. Molly notices that in the first five minutes of Tillie's performance, the entire front row of 60 fish get up, swim off, and demand their money back! Molly doesn't want to carp, but she is afraid that if this continues, the concert will flounder. To Molly's horror, 114 fish leave in the next five minutes, 90% more than the number of fish that left in the first five minutes. If this same rate of departure continues, how long will it take before all 2,200 patrons are gone? Explain in detail how you found your answer using words and numbers.

I don't know how to solve this problem, and I keep on getting decimals, but I don't know if I'm supposed to round them accordingly, or if I did something wrong. I would appreciate some help!​

 

[thunderfury]

Are you able to do this one (same thing, differenyly worded):
$60 is deposited in a savings account; rate of interest is 90% annually.
After how many years will the account have accumulated to $2200 ?

Have you been exposed to logs?

Thankfully, yes. Well I'll try it that way and see what turns out! Thx!