This is a great mathematics challenge for those who love critical thinking problems. Let’s challenge your brain!

## Challenge:

If 8 workers can build a house in 20 days, how many workers is needed to build the house in 4 days?

**A-** 12

**B-** 26

**C-** 32

**D-** 40

**E-** 44

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The correct answer is D.

Keep in mind that the number of workers and the number of days are inversely proportional. It means that with more workers, it takes less time to build a house.

First, find the constant. W (number of workers) × D (days) = 8 × 20 = 160

Then, W × 4 (days) = 160 → W = 40

40 workers are needed to build the house in 4 days!