Assume that Outland specialises in producing skateboards and Inland specialises in producing surfboards. After trade, Outland exports 500 skateboards and imports 100 surfboards. The rate of exchange
▸ is 1:5 skateboards to surfboards.
▸ is 1/5:1 skateboards to surfboards.
▸ is 5:1 skateboards to surfboards.
▸ cannot be determined from this information.