Question 252075
Ok, I have worked this problem for you, scanned it and just need a place to send it.  You find k using the tripling at t=2 and then once you have k, you can find y when t=5.  I get k=(ln 3)/2.
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Anyone wishing to get a copy of this .pdf file, email me with algebra in the subject line and ask for pdf file Dec 220002.  I will send the file without obligation.