The cost of cleaning up pollution in a stream is given by c = 37000 100−p, where c is the cost in dollars to clean p percent of the stream. (for instance, when p is 20, then the formula will calculate the cost to clean up 20 percent of the stream.) p must be greater than or equal to zero and p must be less than what number? why?

This is kenetic energy.

Ohm's law tells you that i = v/r where v is equivalent voltage and r is equivalent resistance of the circuit
since all circuits have the same voltage, your question is really asking which circuit has the lowest total resistance, since the lower the resistance, the higher the current
circuit a has a resistance of 5 ohms; circuit c is in series so has a resistance of 10 ohms; circuit b is in parallel and therefore has a resistance of 2.5 ohms (review your notes on adding resistances in parallel and series); therefore b has the highest current

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