A great Math puzzle to help students develop critical thinking and logic skills in a fun way. Let’s challenge your brain!

## Challenge:

A cubical block of wood weighs 5 kilograms. How much will another cube of the same wood weigh if its sides are three times as long?

**A-** 15

**B-** 30

**C-** 60

**D-** 105

**E-** 135

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The correct answer is E.

Weight is proportional to volume.

Volume of a cube = (one side)\(^3\)

Let x be the side of the first cube. So:

Volume \(= x^3\)

The sides of the second cube are three times as long. So:

Volume \(= (3x)^3 = 27x^3\)

The ratio of the volumes of the old and new cubes will be 1: 27. So, if the first weighs 5 kilograms, the second weighs 27 × 5 kilograms =135 kilogram.