30 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 answer
A) 87 days B) 10 days C) 55 days D) 44 days E) 22 days
Total work to be done = 30 * 40= 
<gadget id="calculator">30 * 40</gadget>
<output>1_200</output>
1200   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)= 1200   40P = 400 =&gt; P = 10 days   Answer:10 days
<result>B</result>
30 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?