If 9 pumps can raise 1085 tonnes of water in 10 days, working 7 hours a day; in how many days will 8 pumps raise 868 tonnes of water, working 9 hours a day?	Pick one:	A) 6	B) 7	C) 8	D) 9	E) 10
Explanation :   Let the required number of days be x. Then,   Less pumps, More days (Indirect Proportion)   Less water, Less days (Direct Proportion)   More hours / day, Less days (Indirect Proportion)   Pumps 8 : 9   Weight 1085 : 868   Hours/day 9 : 7 :: 10 : x   (8 x 1085 x 9 x x) = (9 x 868 x 7 x 10)   x = 9 x 868 x 7 x 10/ (8 x 1085 x 9)   x = 7   Answer : 7
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If 9 pumps can raise 1085 tonnes of water in 10 days, working 7 hours a day; in how many days will 8 pumps raise 868 tonnes of water, working 9 hours a day?