What do you mean this sentence?
the time a pump takes to drain the pool varies inversely with the power in watts of the pump,
The meaning would be : if we have a power in watts greater the time to drag the pool will be less because the relation between power and time is inverse.
40 watts--------------5 hours)
100 watts------------ x
because the relation between power and time is inverse, we multiply directly.
40 watts(5 hours)=100 watts x
x=(200 watts hours) / 100 watts=2 hours.
Answer: the time would be 2 hours. (the new pump is faster)
Answer:
C) 3/2
Step-by-step explanation:

I hope that is useful for you :)
The sign would be negative because there is an odd number of negatives. If there were an even number of negatives it would be positive.
Multiply -5 by -1
The answer would be -5/2
Answer: 52.7856cm
Step-by-step explanation:
Circumference of a circle = 2πr
Note that radius = Diameter / 2 = 16.8/2 = 8.4cm
Circumference = 2πr
= 2 × 3.142 × 8.4
= 52.7856cm
Therefore, the circumference of the circle is 52.7856cm
Perimeter = 2(length + width)
p = 2(10'5" + 9'8")
p = 2(19'13")
p = 38'26"
26" = 2'4"
So...
38' + 2'4" = 40' 4" for the perim,eter