"Eu tenho uma lâmpada que é mais velha do que a da minha casa."

Translation: I have a lamp that is older than the one at my house.

[Endverbraucher]

I have a lightbulb that is older than that of my house.
Accept it!
It's a stupid sentence, but it's a valid translation.

[legatrix]

...Than the one at my house.

[JustinD83]

This sentence is idiotic and designed to trick people into getting it wrong. Bad form, Duolingo.

[Lisa11449]

Why "da"? I would have translated "NA minha casa"...

[Mario542218]

Why is it 'do que' not 'da que' as it is referring to 'lampada' which is feminine?

[MichaelSquire]

I do not like this sentence, its logic is a bit hard to understand. But O.K., you could actually say that. I would not put this in a textbook though.