The diagram shows a unit cube coloured blue. Additional blue unit cubes are glued face-to-face to each of its six faces to form a three-dimensional “cross”. If unit cubes coloured yellow are now glued face-to-face to all the spare faces of this cross, how many yellow unit cubes are required?
Select one option, then click Submit.
6
18
24
30
36
Select an option, then submit.
Sign in or create an account to reveal answers, view the solution, and save your progress. Create a free account to unlock practice and keep track of your work.
Junior Mathematical Challenge 2005 (2005)
One puzzle per day. Cryptarithm, Magic Square, Summit. No sign-up required to play.
Play daily puzzle →Interactive problems and curated lessons—water pouring, magic squares, knight's tour, and more.
Browse library →See how you rank. Top solvers by problems solved correctly. Sign in to climb the ranks.
View leaderboard →Junior Mathematical Challenge 2005 (2005)