Answer: d
Step-by-step explanation:
Volume of water in the tank:

Differentiate both sides with respect to time <em>t</em> :

<em>V</em> changes at a rate of 2000 cc/min (cubic cm per minute); use this to solve for d<em>h</em>/d<em>t</em> :


(The question asks how the height changes at the exact moment the height is 50 cm, but this info is a red herring because the rate of change is constant.)
<span>461.81 cm^3 .................................</span>
This type of sampling would be Random Sampling.
Answer:
negative correlation ( age of the car increases value of it decreases)