Solve the all parts of given question:
Question: John who is a member of NGO missed the meeting of his protest group at the refinery and now needs to get to the oil rig in the shortest time to join the demonstrators trying to disrupt the work of the petroleum company. John can run at 10 km/h by can paddle only 3 km/h.
Part A: How far from the refinery should John enter the water?
Part B: What is the minimum time it will take to get the oil rig? (L = 12 km, d = 4 km).
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