D
Let capacity of A be x litres
Then capacity of B = x/2 litres
Capacity of the dumper = 120x litres
Required number of turns = 120x/ x =x/2
= 2 (120x)/3x
=2430x/3x
=80.
A large cistern can be filled by 2 pipes P & Q in 120 mins and 80 mins respectively. How many mins will it take to fill the cistern from empty state if Q is used for half the time and P & Q fil it together for the other half? A) 2hrs B) 1hr C) 3hrs D) 4hrs Answer : B Part filled by (P+Q) in 1 min = 1/120 + 1/80 =2+3/240 = 5/240 = 1/48 Suppose the cistern is filled in x mins then, x/2 (1/48 + 1/80) = 1 x/2(5+3/240)=1 8x/480 = 1 x=480/8 x= 60 mins or 1 hr...
A dumper is normally filled in 18 hours but takes 6 hours longer to fill because of a leak in the bottom of the dumper. If the dumper is full the leak will empty it in how many hours? A) 76 hours B) 78 hours C) 72 hours D) 74 hours Answer : C Work done by leak in 1 hr=(1/18-1/24) =>4-3/72 =>1/72 Leak will empty the dumper in 72 hours...
Two pumps M and N can separately fill a dumper in 36 minutes and 45 minutes respectively. Both the pumps are opened together but 12 minutes after the start the pump M is turned off. How much time will it take to fill the dumper? A) 9 min B) 10 min C) 30 min D) 32 min Answer : C 12/36 + x/45 = 1 (12*5)/180+4x/180=1 60+4x=180 4x=120 X=120/4=30min...
Two taps M and N can alone fill a tank in 80 minutes and 120 minutes respectively. But due to a leakage of tank, it took 12 more minutes to fill the tank. In how many hours, the leak can alone empty the full tank? A) 240 B) 230 C) 248 D) 256 Answer : A A and B can fill tank in (1/80 + 1/120) = 1/48 so 48minutes But it took 12 more minutes, this means the tank got full in 48+12= 60 minutes So (1/80 + 1/120 – 1/x) = 1/60 1/X=1/80+1/120-1/60 Solve, x = 240...
Two filling tap can fill a dumper in 14 and 28 min. respectively and when the waste tap is open, they can together fill it in 35 min. The waste pipe can empty the full dumper in – A) 152/9 hrs. B) 137/7 hrs. C) 60/9 hrs. D) 140/11 hrs. Answer : D 1/14 + 1/28 – 1/35 =>10 + 5 – 4/140 =>11/140 =>140/11 => hence answer is 140/11 hours....
50.5k questions
47.1k answers
240 comments
7.0k users
