GK 2017 Q20
20. Anastasia's tablecloth has a regular pattern, as shown in the diagram.
What percentage of her tablecloth is black?
- A 16
- B 24
- C 25
- D 32
- E 36
Grey Kangaroo 2017, Question 20. © UK Mathematics Trust. Original paper on ukmt.org.uk
Answer: D 32
Divide the tablecloth into 25 equal squares as shown. Half of each of the 16 outer squares is coloured black which is equivalent to 8 complete squares. Therefore the percentage of the tablecloth that is coloured black is
\(\dfrac{8}{25} \times 100 = 32\).
Solution © UK Mathematics Trust, from the GK 2017 solutions.