CAT Quantitative Ability Questions | CAT TIme, Speed, Distance and Work questions
CAT/2005
Question . 75
A chemical plant has four tanks (A, B, C and D) each containing 1000 litres of a chemical. The chemical is being pumped from one tank to another as follows :
From A to B @ 20 litres/minute
From C to A @ 90 litres/minute
From A to D @ 10 litres/minute
From C to D @ 50 litres/minute
From B to C @ 100 litres/minute
From D to B @ 110 litres/minute
Which tank gets emptied first, and how long does it take (in minutes) to get empty after pumping starts?
Explanatory Answer
Method of solving this CAT Quantitative Ability Question from TIme, Speed, Distance and Work question
(c) Water entering (positive sign) or leaving (negative sign) representation :
Tank A = (90 – 20 – 10) = 60 litres/min.
Tank B = (110 – 100 + 20) = 30 litres/min.
Tank C = (100 – 90 – 50) = –40 litres/min
Tank D = (10 + 50 – 110) = –50 litres/min.
Hence, Tank D gets emptied first.
Time taken by tank D to get empty =1000/50 = 20 min