Question

10 masons can build a wall working 7 hours a day in 12 days in how much days change the work be completed by 14 persons working 8 hours a day

Answer 1

let 14 masions complete work by working 7 hours in day in = x days

10 masions complete work in = 12*7=84 hours

14 persons complete work in = x * 8 =8x hours

This is case of inverse variation ,

So , 10 * 84 = 14 * 8x
840 = 112x
x = 7.5 days OR 7 and half days