Answer:
The amount of the chemical flows into the tank during the firs 20 minutes is 4200 liters.
Step-by-step explanation:
Consider the provided information.
A chemical flows into a storage tank at a rate of (180+3t) liters per minute,
Let
is the amount of chemical in the take at <em>t </em>time.
Now find the rate of change of chemical flow during the first 20 minutes.

![\int\limits^{20}_{0} {c'(t)} \, dt =\left[180t+\dfrac{3}{2}t^2\right]^{20}_0](https://tex.z-dn.net/?f=%5Cint%5Climits%5E%7B20%7D_%7B0%7D%20%7Bc%27%28t%29%7D%20%5C%2C%20dt%20%3D%5Cleft%5B180t%2B%5Cdfrac%7B3%7D%7B2%7Dt%5E2%5Cright%5D%5E%7B20%7D_0)


So, the amount of the chemical flows into the tank during the firs 20 minutes is 4200 liters.
It would take 15 weeks and they would meet at 178lbs.
The sale price of the jeans would be $73.09
Multiple 15 by 6, the answer is 90 square cm