20 men can do a work in 40 days. When should 20 men leave the work so that the entire work is completed in 40 days after they leave the work?	Choose the correct option:
A) 0 days
B) 10 days
C) 20 days
D) 30 days
E) 40 days
Total work to be done = 20 * 40= 
<gadget id="calculator">20 * 40</gadget>
<output>800</output>
800   Let 20 men leave the work after 'P' days, so that the remaining work is completed in 40 days after they leave the work.   40P + (20 * 40)= 800   40P = 0 =&gt; P = 0 days   0 daysNSWER:0 days
<result>A</result>
20 men can do a work in 40 days. When should 20 men leave the work so that the entire work is completed in 40 days after they leave the work?