Plz help me! I've tried following he instructions as it says how to do it in the question help but it keeps saying its wrong! This is the final check! Plz help!

Francis is getting new carpet tiles in his living room and den. his living room and den are connected. he needs to figure out how much carpet he needs and the cost involved. if each tile costs $2.00 per sq ft, how much would it cost to have new tile put in the den? a) $24 b) $36 c) $48 d) $54 plz awnser soon