KVPY Government Jobs Exams

Three taps A, B, C fill up a tank independently in 10 hr, 20 hr, 30 hr, respectively. Initially the tank is empty and exactly one pair of taps is open during each hour and every pair of taps is open at least for one hour. What is the minimum number of hours required to fill the tank?
option
(A) 8
(B) 9
(C) 10
(D) 11

Read Solution (Total 1)

each fill 1/10 , 1/20 , 1/30 in 1 hr ...
adding them we get 6/60=1/10
that is 1/10th work in done in 1 hr
so the whole work will be done in 10 hours
4 years agoHelpfull: Yes(0) No(0)

KVPY Other Question

Two friends A and B are 30 km apart and they start simultaneously on motorcycles to meet each other. The speed of A is 3 times that of B. The distance between them decreases at the rate of 2 km per minute. Ten minutes after they start, A's vehicle breaks down and A stops and waits for B to arrive. After how much time (in minutes) A started riding, does B meet A?
option
(A) 15
(B) 20
(C) 25
(D) 30 In a thermally isolated system, two boxes filled with an ideal gas are connected by a valve. When the valve is in closed position, states of the box 1 and 2, respectively, are (1 atm, V, T) and (0.5 atm, 4V, T). When the valve is opened, the final pressure of the system is approximately
option
(A) 0.5 atm
(B) 0.6 atm
(C) 0.75 atm
(D) 1.0 atm