Question

36 men can reap a field in 12 days. How many men must be engaged to reap the same field in 27 days?

Answer 1

To do this we use the proportion's funda.

       men needed                         to do work in day(s)

               36(x1)                                           12(y2)

                  x2                                                  27(y2)

now we see, that if we decrease the no. of men working then we require more time to finish the same work.

this means the equations are in inverse/indirect proportion.

so the formula of inverse proportion is = x1/x2  =  y1/y2

using the formula   :  36/x2 = 12/27

                                ;  36 X 27  =   x2 X 12            [cross multiplication]

                                ;  (36 X 27)/12 = x2

                                ;  81 = x2

if x2 is the value of 81 then it means: the number of men required to complete the same work in 27 days is 81.

Done