The first pump empties half the pond in 3 hours, so in 1/6 that time (1/2 hour), it empties (1/6)·(1/2) = 1/12 of the pond.
The second pump empties the other 5/12 of the pond in that half hour, so has a pumping rate of (1/2 h)/(5/12 pond) = (6/5 h)/pond.
The second pump could do the entire job alone in 1 hour and 12 minutes.
Answer:
The value of x component changes at a rate of
units per second
Step-by-step explanation:
We are given that 
Differentiating on both sides with respect to time we get

It is given that
Solving for
we get

It’s C. I hope this helps
Age is the independent variable
This is already in scientific notation