A building has eight floors with six apartments on each floor and two roof apartments. If each apartment has four electrical circuits, how many total circuits are there?

• A. 180
• B. 200
• C. 220
• D. 240

Answer: (B)

Count all the apartments first, then multiply by the number of circuits per apartment. Eight floors times six apartments per floor gives 8 × 6 = 48 regular apartments. There are two roof apartments, so add 2 to get 50 total apartments. Each apartment has four circuits, so total circuits = 50 × 4 = 200.

If you skip the roof apartments, you’d get 48 × 4 = 192, which isn’t correct because the roof units also need circuits.