A person decided to build a house in 100 days. He employed 100 men in the beginning and 100 more after 20 days and completed the construction in stipulated time. If he had not employed the additional men , how many days behind schedule would it have been finished? Choose the correct choice
A) 40
B) 80
C) 70
D) 60
E) 50
200 men do the rest of the work in   100-40= 
<gadget id="calculator">  100-40</gadget>
<output>60</output>
60 days   100 men can do the rest of the work in 60*200/100= 
<gadget id="calculator">60*200/100</gadget>
<output>120</output>
120 days   Required number of days= 120-60= 
<gadget id="calculator">120-60</gadget>
<output>60</output>
60 days   Answer is 60
<result>D</result>
A person decided to build a house in 100 days. He employed 100 men in the beginning and 100 more after 20 days and completed the construction in stipulated time. If he had not employed the additional men , how many days behind schedule would it have been finished?