Answer:

Step-by-step explanation:
The rates are additive: you can calculate the<em> inlet </em>rate and the <em>outlet</em> rate and add them algebraically, i.e. the inlet rate will be positive and the outlet rate will be negative.
<u>1. Inlet rate:</u>

<u />
<u>2. Outlet rate:</u>

<u>3. Net rate:</u>

<u>4. Time to fill the vat</u>


Step-by-step explanation:
1.
(chain rule)
2 

Answer:
p < 0
Step-by-step explanation:
Given
- 3(p - 7) > 21
Divide both sides by - 3, reversing the symbol as a result of dividing by a negative quantity.
p - 7 < - 7 ( add 7 to both sides )
p < 0
Multiply two kilometers per day by 1000 meters per kilometer to get 2000 meters per day. Multiply by two days to get 4000 meters, which is the answer.