HKIMO 2017 Grade 6 National Final (Heat) Set 04 Question 19

A square is formed from 722 rectangles measuring 1 cm by 2 cm. Find the decrease in total perimeter, in cm.

Source glossary (English–Vietnamese): Square: hình vuông; Rectangle: hình chữ nhật; Decrease: giảm đi; Perimeter: chu vi.