10 men working 6 hrs per day manufacture 200 shoes in 18 days. How many hours a day must 15 men work to manufacture the same 200 shoes in 12 days?	Choose the correct answer
A) 6
B) 10
C) 12
D) 15
E) 17
Explanation :   Solution: Let the required number of hours be x.   More men, less hours per day (Indirect proportion)   Less days, more working hours per day (Indirect proportion)   men 15 : 10   } : : 6 : x   days 12 : 18   .'. 15*12*x = 10*18*6   =&gt; x = 10*18*6/(15*12)   =&gt; x = 6   6nswer : 6
<result>A</result>
10 men working 6 hrs per day manufacture 200 shoes in 18 days. How many hours a day must 15 men work to manufacture the same 200 shoes in 12 days?