Brain Teasers
Wood 2
A block of wood, in the form of a cuboid 4" x 7" x 14", has all its six faces painted pink. If the wooden block is cut into 392 cubes of 1" x 1" x 1", how many of these would have pink paint on them?
Answer
The 1" x 1" x 1" cubes that do not have any pink paint on them will be at the core of the wooden block. This core will be 2" x 5" x 12", and will contain 120 cubes.Out of a total of 392 cubes, there are 120 cubes without any pink paint on them. Therefore, the remaining 272 cubes will have one, two or three sides with pink paint on them, depending on whether they were at the face, edge or corner of the wooden block.
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Comments
Good teaser.
math-y person submitted this.
I'm not any good with math,
but for some strange reason I enjoyed this teaser. I didn't get the answer right. BUT I do like pink.
but for some strange reason I enjoyed this teaser. I didn't get the answer right. BUT I do like pink.
HOLY hardness..... but I liked it. Great Job
Fun stuff, and practical, too!
Good one, easy but hard.
Very nice. I was looking for a complicated solution but the answer was so simple.
But aren't you double counting pink bricks on the edges and corners?
bevillmen23, I believe they are.
My math:
7*14*2 + 7*4*2 + 14*4*2 = 364
Each corner has been counted four times and each edge piece twice.
Corners
8*3 = 24
Edges
12*4 + 2*4 + 5*4 = 76
So, I think the answer is 364 - 24 - 76 = 264.
My math:
7*14*2 + 7*4*2 + 14*4*2 = 364
Each corner has been counted four times and each edge piece twice.
Corners
8*3 = 24
Edges
12*4 + 2*4 + 5*4 = 76
So, I think the answer is 364 - 24 - 76 = 264.
Nmallare your logic is sound, but the corners are only counted 3 times so your total number should still come 272. Different approach but same answer.
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