After Carl had stacked up 11 chairs in the canteen after a parade, 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 61.2 cm above that of the first. Thirdly, the chairs reached a height of 251.4 cm. What is the height of each chair?
Number of chairs that contributed to the height of 61.2 cm above the first chair
= 5 - 1
= 4

Height increase with each additional stacked chair
= 61.2 ÷ 4
= 15.3 cm

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

Height increase of 10 additional stacked chairs
= 10 x 15.3
= 153 cm

Height of one chair
= 251.4 - 153
= 98.4 cm

Answer(s): 98.4 cm