A rectangular cardboard is 50 mm by 12 mm. A square of side 4 mm is cut from it. What area remains?
Note
First find the rectangle area: 50 × 12 = 600. The cut-out square area is 4 × 4 = 16. Remaining area = 600 − 16 = 584 square mm. For composite figures, split the shape into simple parts or subtract the removed part. Here the square is cut out, so its area must be subtracted from the rectangle area, not added. So the correct choice is 584 mm².