1.A cistern has 3 pipes A, B and C. A and B can fill it in 3 hours and 4 hours respectively while C can empty the completely filled cistern in 1 hour. If the pipes are opened in order at 3, 4 and 5 p.m. respectively, at what time will the cistern be empty?
(1) 6 : 15 p.m.
(2) 7 : 12 p.m
(3) 8 : 12 p.m.
(4) 8 : 35 p.m.
(5) None of these
2.A steamer goes downstream from one
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