Three pipes A, B and C can fill a tank from empty to full in 30 minutes, 20 minutes, and 10 minutes respectively. When the tank is empty, all the three pipes are opened. A, B and C discharge chemical solutions P,Q and R respectively. What is the proportion of the solution R in the liquid in the tank after 3 minutes?
5/11
7/11
6/11
8/11
Explanation:
LCM(30,20,10)=60
Suppose capacity of the tank is 60 litre. Then,
quantity filled by pipe A in 1 minute =60/30=2 litre.
quantity filled by pipe B in 1 minute =60/20=3 litre.
quantity filled by pipe C in 1 minute =60/10=6 litre.
Quantity filled by pipe C in 3 minutes
=3×6=18 litre.
Quantity filled by pipe A,B,C together in 3 minutes
=3(2+3+6)=33 litre.
Required proportion =18/33=6/11
LCM(30,20,10)=60
Suppose capacity of the tank is 60 litre. Then,
quantity filled by pipe A in 1 minute =60/30=2 litre.
quantity filled by pipe B in 1 minute =60/20=3 litre.
quantity filled by pipe C in 1 minute =60/10=6 litre.
Quantity filled by pipe C in 3 minutes
=3×6=18 litre.
Quantity filled by pipe A,B,C together in 3 minutes
=3(2+3+6)=33 litre.
Required proportion =18/33=6/11