John is trying to drain a swimming pool. He has two pumps, but he can only use one at a time. He knows that the time a pump take

Question

3 years ago

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John is trying to drain a swimming pool. He has two pumps, but he can only use one at a time. He knows that the time a pump take

s to drain the pool varies inversely with the power in watts of the pump. His old pump is a 40 watt pump, and it can drain the pool in 5 hours. How long would the job take if he uses his new 100 watt pump?

Mathematics

1 answer:

xeze [42] · Answer 1 · 2022-03-08T19:14:24+03:00

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)