If 4 men working 10 hours a day earn Rs. 1600 per week, then 9 men working 6 hours a day will earn how much per week?  Select:
A) Rs 840
B) Rs 1320
C) Rs 1620
D) Rs 2160
E) None of these
Explanation :   (Men 4:9) : (Hrs/Rs 2160ay 10:6) :: 1600 : x   hence 4 * 10 *x = 9 * 6 * 1600   or x = 9*6*1600/ 4*10 = 2160   Answer : Rs 2160
<result>D</result>
If 4 men working 10 hours a day earn Rs. 1600 per week, then 9 men working 6 hours a day will earn how much per week?