incorrect 4.3 Quiz answer ref. Handynummer

In the question below from Quiz 4.3, is asks for the masculine form. But when I did so, i.e. der Handynummer, I was told it was incorrect and should be "die Handynummer", which is feminine. What is the German word for "cell phone number" (m)? das Handynummer der Handynummer die Handynummer die Handienummer

Yeah i found that annoying. I ended up just selecting die Handynummer so that i could get 100%. If you email customer support / feedback they will certainly change this. Ill send off an email to them now.

Hello TueffelHunden and Kenneth, Sorry for late reply. "Die Handynummer" is correct. Handynummer is a compound word of the two nouns "das Handy" and "die Nummer". Compound words have the gender of the last noun in the word. Other examples: "Die Autotür". It is "das Auto" for itself but Tür is femine gender. I hope that helps! Paul