Two men and 7 children complete a certain piece of work in 4 days while 4 men and 4 children complete the same work in only 3 days. The number of days required by 1 man to complete the work is Choose the correct choice from the following choices:
A) 60 days
B) 15 days
C) 6 days
D) 51 days
E) 50 days
Two men and 7 children complete a certain piece of work in 4 days   or 8 men and 28 children complete a certain piece of work in 1 days   4 men and 4 children complete the same work in only 3 days.   or 12 men and 12 children complete the same work in only 3 days.   so 8 men +28 children = 12 men +12 children   1Man = 4 children   4 men and 4 children complete the same work in only 3 days   or 4 men and 1 man ( in place of 4 children ) complete the same work in only 3 days   or 5 men complete the same work in 3 days   or 1 man will complete the same work in 5* 3= 
<gadget id="calculator">5* 3</gadget>
<output>15</output>
15 days   ANSWER:15 days
<result>B</result>
Two men and 7 children complete a certain piece of work in 4 days while 4 men and 4 children complete the same work in only 3 days. The number of days required by 1 man to complete the work is