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1) The 2nd person's eye sight height is 1.4m, so 0.8 will be taken away as the height of the first person is 0.8m. This is then the height of the 2nd spectator's chair; 0.6m

3)0.4,0.6,0.8,1,1.2,1.4,1.6,1.8,2,2.2,2.4,2.6,2.8,3,3.2,3.4,3.6,3.8,4,4.2,4.4,4.6,4.8,5,5.2,5.4,5.6,5.8,6,6.2,6.4,6.6,6.8,l7,7.2,7.4,7.6,7.8,8,8.2,8.4 <-- 40th person chair height