   SEARCH HOME Math Central Quandaries & Queries  Please help me with this question: At First, Tank A was completely filled with water. The tap from Tank A was then turned on and water flowed out at a constant rate. The water which flowed out was collected into Tank B. At the end of 6 minutes, Tank A was 2/3 full. After a further 8 minutes, Tank A had 2.4 liters of water left while Tank B was completely filled with water. Find the capacity of Tank B. Hi Noel,

I want to introduce a new measurement of volume called a TANK. A TANK is the volume of tank A in liters.

The water is flowing out of tank A into tank B at a constant rate. After 6 minutes, $\frac13$ of the volume of tank A has flowed into tank B. Thus the water is flowing at a rate of

$\frac{\frac13 \mbox{ TANK}}{6 \mbox{ minutes}}= \frac{1}{18} \frac{\mbox{TANK}}{\mbox{ minute}}.$

After a further $8$ minutes, that is in $6 + 8 = 14$ minutes, the amount that has flowed out is

$\frac{1}{18} \frac{\mbox{TANK}}{\mbox{ minute}} \times 14 \mbox{ minutes} = \frac{7}{9} \mbox{TANK}.$

Hence the 2.4 liters remaining is $\large \frac29 \mbox{ TANK}.$ How big is a TANK? What is the capacity of tank B?

Penny     Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.