Question

on the global grid a location 20 north of the equator and 30 west of the prime meridian would be:

Answer 1

I would suggest going on Google Images and searching 'latitude and longitude map.'

Answer 2

The answer is 20N and 30W
and not 30W and 20N because it's a general cartographic rule of thumb that when reading Latitude and Longitude, Latitude is to be read before Longitude.