If 0.274 moles of a substance weighs 62.5 g, what is the molar mass of the substance, in units of g/mol?

Here's a trick:

The unit is g/mol

And you imagine "/" as a division.

So gram is divided by the number of moles

Therefore, the molar mass = 62.5g/0.274mol = 228.1 g/mol (correct to one decimal place)