Acrew team rows a boat at a rate of 20 km/h in still water. in practice on a river, the team rows for 30 minutes up the river (against the current), and then for 30 minutes down the river (with the current). the speed of the river current is 1.5 km/h. how much farther did they travel in the second 30 minutes?

In the second 30 mins, the speed should be 20 + 1.5 = 21.5 km/h

So S = 21.5 * 30/60 = 10.75 km

Domain eukarya; kingdom plantae should be the answer.

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