2010 W Final Q7E ethyl before methyl?

[Kiara1F]

Q7E. give IUPAC name of methyl ethyl amine

Answer: N- methylethanamine

Why isn;t the answer N-ethylmethanamine ( where the e in ethyle comes before the m in methyl in the name prioritization?)
Would N-ethylmethanamine be wrong?

[Chem_Mod]

Since ethyl is the longest hydrocarbon chain attached to N, that should be the compounded name with the -amine suffix. Methane is a shorter chain substituent, so it is added onto the rest of the name "ethanamine". N-ethylmethanamine would be wrong because you would be treating the shorter hydrocarbon chain as the "main" chain attached to the N.

This question is testing on your knowledge of the subtle differences between common naming and IUPAC naming. I hope this makes sense.