### Review Comments for Number 15

### Dr. Sarah's Comments

To see that the d.e. is 2-x(t)/(1+t),
notice that 2gal/min*1lb/gal = 2lb/min is the input rate,
while the output rate is 1gal/min*x(t) lb / (1+t) gal,
since there is 1+t gal in the tank after t minutes
(we start with 1 gal, and we increate 1 gal/minute (2-1).
Also notice that after t=9, the tank will overflow, since the tank
holds 10 gal, and there is 1+t gal in the tank after t minutes
(so at t=9, the tank will be full)

Great otherwise!

### Peer Review Comments

nice transition to the board for re-explanation of the problem,
explained graphs very well

very good! great explanations!

wicked good, good plots, very interesting, presented it well

worksheet has good explanations, but the questions
need to be in the worksheet in some form. Good presentation.

Nice, they know where they are going

Excellent work! That was a TOUGH problem and they explained it
very well!

good understanding of problem; used Maple very efficiently; very good

good manipulation of Maple. I think I actually understand something!

You might explain in text how you got the d.e. You need to
explain where t=9 came from in more depth. Very good
explanation; good job!!

They seemed to do well with this given problem

Probably explore different values by inc. time and the
value when it overflowed. Overall good job.

hard question to explain, good job

good, a little confusing, talked too long

long and complicated problem, but their explanation was thorough and
easy to understand.

excellent presentation. well done and thought out.
Handled questions very well. very long project. they did
very well.

The explanations written on the board were very helpful,
but these should have been put in text in the worksheet.
Good explanation of defield. Good text comments on the rest.
Good job and great effort on such a long problem.

How would salt concentration increase if initial amount is
(for example) 2 pounds/gallon? Mixing the solution with incoming
1/1 solution would cause that to decrease towards the proportion
of the incoming soluition?Woooo, lots of work. Good comments
in problem.

good job!!!