Geometry Puzzle – Challenge 70
A cubical wood block weighs 5 kg. How much does a cube of the same wood weigh if its sides are three times as long? Weight is proportional to volume, and cube volume scales by the cube of the linear factor. So the new cube has 3^3 = 27 times the volume, and 27 times […]
Geometry Puzzle – Challenge 69
A rectangle’s length grows by 20%, so length goes from L to 1.2L. To keep the area the same, the width has to shrink by a compensating factor. Solve: W times 1.2L = W’ times 1.2L should equal the old area W times L, so W’ = W/1.2 = (5/6) W. That is a decrease […]
