 ### Challenge from 4. December

Christmas Candles

Authors: Cor Hurkens, Hennie ter Morsche

Project: 4TU.AMI

Challenge:

The packer-pixy Paco packs fifteen Christmas candles upright into a box with a square base. Each candle is shaped like a cylinder with a circle of radius 1 cm as its base. The picture shows the base of the box as a square and the bases of the fifteen candles as fifteen circles. The picture shows which candles touch each other and which candles touch the boundary of the box. The side length s of the square can be written in the form s = a+√b+√c(measured in centimeters) with three integers a, b, c.

What is the value of the sum a+b+c of these three integers?

Artwork: Frauke Jansen Possible answers:

1. The sum of a, b, c is 8.

2. The sum of a, b, c is 9.

3. The sum of a, b, c is 10.

4. The sum of a, b, c is 11.

5. The sum of a, b, c is 12.

6. The sum of a, b, c is 13.

7. The sum of a, b, c is 14.

8. The sum of a, b, c is 15.

9. The sum of a, b, c is 16.

10. The sum of a, b, c is 17.

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