After Ethan had stacked up 11 chairs in the canteen after a celebration, he noticed 3 things. Firstly, each of the chairs was stacked the same height above the other. Secondly, the foot of the seventh chair was 85.2 cm above that of the first. Thirdly, the chairs reached a height of 240.1 cm. What is the height of each chair?
Number of chairs that contributed to the height of 85.2 cm above the first chair
= 7 - 1
= 6

Height increase with each additional stacked chair
= 85.2 ÷ 6
= 14.2 cm

Number of chairs stacked on top of the first chair
= 11 - 1
= 10

Height increase of 10 additional stacked chairs
= 10 x 14.2
= 142 cm

Height of one chair
= 240.1 - 142
= 98.1 cm

Answer(s): 98.1 cm