Hi, I have a question regarding finding the MRT. The question from the textbook is:

'In autarky, Japan's production and consumption points along its production possibilitiesschedule are assumed to be 500 tons of steel and 600 autos. Draw a line tangent to Japan's autarky point, and from it, calculate Japan's MRT of steel into autos. In autarky, South Korea's production and consumption points along its production possibilities schedule are assumed to be 200 tons of steel and 800 autos. Draw a line tangent to South Korea's autarky point, and from it, calculate South Korea's MRT of steel into autos.'

Please let me know how I can find the MRT? I have a photo of the PPF and the Steel and Auto Production included.