HKIMO 2020 Grade 5 National Final (Heat) Set 01 Question 20

27 small cubes with side length 1 are combined. According to the figure below, find the surface area.



Source glossary (English–Vietnamese): Cube: khối lập phương; Side length: độ dài cạnh; Pattern: quy luật; Surface area: diện tích toàn phần.