14 persons earn amount = 400
1 person earns amount = 400/14 = 200/7
Lets suppose x Person earn 600
Then 1 person earns: 600/x = 200/7
Cross multiplying gives: 600/200 = x/7 ----> x = 7 * 3 = 21
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6 people build wall in 16 days
1 person will build wall in = 16 * 6 = 96 days
8 person will build same wall in = 96/8 = 12 days
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Height of wall built by 4 masons in 4 hours = 4 ft
Height of wall built by 4 masons in 1 hours = 4 ft/4 = 1 ft
Height of wall built by 1 masons in 1 hours = 1/4 ft
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These were quite simple questions By the way 