After Perry had stacked up 8 chairs in the canteen after a conference, he noticed 3 things. Firstly, each of the chairs was stacked the same height above the other. Secondly, the foot of the fifth chair was 21.6 cm above that of the first. Thirdly, the chairs reached a height of 125.7 cm. What is the height of each chair?
Number of chairs that contributed to the height of 21.6 cm above the first chair
= 5 - 1
= 4

Height increase with each additional stacked chair
= 21.6 ÷ 4
= 5.4 cm

Number of chairs stacked on top of the first chair
= 8 - 1
= 7

Height increase of 7 additional stacked chairs
= 7 x 5.4
= 37.8 cm

Height of one chair
= 125.7 - 37.8
= 87.9 cm

Answer(s): 87.9 cm