A certain number of men can do a work in 20days. If there were 4men more it could be finished in 5days less. How many men are there?	Choose the correct choice from the following answers:
A) 10  B) 12  C) 15  D) 20  E) 18
Original number of workers = 4 * (20-5)/5= 
<gadget id="calculator">4 * (20-5)/5</gadget>
<output>12</output>
12men   Answer is 12
<result>B</result>
A certain number of men can do a work in 20days. If there were 4men more it could be finished in 5days less. How many men are there?