A contractor hires 100 men to finish a job in 50 days. After 36 days, n men leave. After some more days, the contractor hires 2n more men to complete the job on time. For how many days did these 2n men work?  Choose the correct choice
A) 20	B) 18	C) 16	D) 12	E) 7
Step1: Find Each day what % of work is finished ; it requires 50 days to complete which means each day 1/50= 2% work will be completed.   Step 2 : After 36 Days = 36* 2= 
<gadget id="calculator">36* 2</gadget>
<output>72</output>
72% of work is finished. remaining is 28% ( which means if same 100 men were about to complete the job they would have required 14 more days)   Step3: Let us assume all people have left job. therefore contractor hires 2n people. initially it was taking 14 days to compete for n people. at present 2n people are present to finish job. hence 7 more days.   7
<result>E</result>
A contractor hires 100 men to finish a job in 50 days. After 36 days, n men leave. After some more days, the contractor hires 2n more men to complete the job on time. For how many days did these 2n men work?