"Det er ikke praktisk."
Translation:It is not convenient.
"Praktisk" is convenient in the way that a shovel is convenient for digging a hole. "Bekvemt" is convenient in the way that having the hotdog stand closer to your seat is convenient. "Bekvemt" also overlaps with "behageligt" in meaning comfortable.
How come it is not praktiskt? Are there certain words that do not take a 't' suffix?
Great question! Adjectives that end in -sk don't add the T for neuter gender or when they are adverbs. One-syllable words can though (unless they are nationalities, like fransk or tysk), but that's more or less optional (so for instance frisk and friskt both work for neuter words, or "t-words").
I wrote that 'it's inconvenient' - apparently this is the wrong answer. I don't mind... I like challenging Duollingo as I learn! But there's nothing wrong with my answer.