As we have calculated, the equilibrium price will be the one that clears the market. As not all of the capacity can be covered by large tankers, the price that compensates for the operating cost of the marginal capacity, i.e. medium tankers (like your friend's), will be paid for all actors on the market. While large tankers due to their lower operating cost are still making a profit, medium-sized tankers don't. Their only value is the scrap value, just as the small tankers' value.
If the interviewee was very fast, you can repeat the exercise, but with a fixed demand of 65m m³ ceteris paribus.
Results:
Market clearing price will be $100,000 per 100,000 m³ oil.
Large tankers: Profit = Revenue - Cost = (Capacity * price / 100,000 m³) - $200,000 = 400,000 m³ * $100,000 / 100,000 m³ - $200,000 = $ 200,000
Medium tankers: Profit = Revenue - Cost = (Capacity * price / 100,000 m³) - $150,000 = 200,000 m³ * $100,000 / 100,000 m³ - $150,000 = $ 50,000
Small tankers: Profit = Revenue - Cost = (Capacity * price / 100,000 m³) - $100,000 = 100,000 m³ * $100,000 / 100,000 m³ - $100,000 = $ 0
Value:
Large tankers: $2m
Medium tanker: $0.5m
Small tanker: $0 or scrap value only.