need help with Macro Econ Exchange Rate question…?

I can’t seem to wrap my head around this. I can usually figure out USD to CAD conversion. (for example.USD exg 10% usd, usd = .10cad)

But these international rates are getting me.

country $ of shirt exchange rate
canada 31.50 -
china 126 yuan 5.3
mexico 168 6

what is the cheapest country to buy the shirt in?

how do you figure out the currency exchange and how much 128 yuan are in canadian dollars?