A Canadian, driving in the U.S.A. fuels their car at a cost of US$1.44 per gallon (US). The current monetary exchange rate is 0.648 US$/Can$. The density of the fuel is 0.648 g/mL. What is the mass of Can$35.00-worth of this fuel?


I don't get this.. .
D:

In converting units the procedure is to start with the quanity you know and multiply by conversions that mathematically are equivalkent to 1. For example, if the denisty of fuel is 0.648 g/mL, that means that 0.648g = 1 mL, so multiplying by 0.648g/mL is the same as multiplying by 1. Conversely, you could also divide by 0.648 g/mL, or multiply through by 1/.648 mL/g. So to convert from what you are given - $US/gal - to what you want - $Can/g, you need to multiply (or divide) by unit conversions to get the units the way you want, like this:

$Can/g = $US/Gal * Gal/g *$Can/$US

So you now need to determine the conversion factor for Gal/g. You can do that like this:

Gal/g = Gal/mL * mL/g

Put it all together:

$Can/g = $US/Gal * Gal/mL * mL/g *$Can/$US

You are given that $US/Gal = $1.44, mL/g = 1/.648, and $Can/$US = .648 You will have to look up what the conversion for mL/Gal is.