Question 1206760
A contractor undertook to do a certain piece of work in 9 days.
 He employed certain number of men, but 6 of them being absent from the very first day, the rest could finish the work in 15 days. The number of men originally employed were:
<pre>
Use the worker-time-job formula, which is:

{{{(W[1]T[1])/J[1]}}}{{{""=""}}}{{{(W[2]T[2])/J[2]}}}

where

W<sub>1</sub> = the number of workers in the first situation. 
T<sub>1</sub> = the number of time units (days in this case) in the first situation.
J<sub>1</sub> = the number of jobs in the first situation.

W<sub>2</sub> = the number of workers in the second situation.
T<sub>2</sub> = the number of time units (days in this case) in the second situation.
J<sub>2</sub> = the number of jobs in the second situation.

W<sub>1</sub> =  n             W<sub>2</sub> = n-6     
T<sub>1</sub> =  9             T<sub>2</sub> = 15 
J<sub>1</sub> =  1             J<sub>2</sub> = 1

{{{(W[1]T[1])/J[1]}}}{{{""=""}}}{{{(W[2]T[2])/J[2]}}}

{{{(n*9)/1}}}{{{""=""}}}{{{((n-6)*15)/1}}}

{{{9n}}}{{{""=""}}}{{{(15n-90)}}}

{{{9n-15n}}}{{{""=""}}}{{{-90}}}

{{{-6n}}}{{{""=""}}}{{{-90}}}

{{{n}}}{{{""=""}}}{{{15}}}

number of men originally employed was: 15

Edwin</pre>