SOLUTION: A 100 liter storage tank is to be filled with solvent from two pipes, A and B. solvent A is pumped at a rate of 25litres/min. Solvent B is pumped at a rate of 40 liters/min. How ma

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A 100 liter storage tank is to be filled with solvent from two pipes, A and B. solvent A is pumped at a rate of 25litres/min. Solvent B is pumped at a rate of 40 liters/min. How ma      Log On


   

Question 909693: A 100 liter storage tank is to be filled with solvent from two pipes, A and B. solvent A is pumped at a rate of 25litres/min. Solvent B is pumped at a rate of 40 liters/min. How many additional minutes are required to fill up the storage tank, if pipe A is opened 4 minutes before pipe B?
Answer by josgarithmetic(39613) About Me  (Show Source):
You can put this solution on YOUR website!
Let t be the unknown minutes during both pipes open together;

RATES------------------
Pipe A, 25 liters/minute
Pipe B, 40 liters/minute
A&B, 65 liters/minute

The question is a uniform rates situation, highlight_green%28RT=V%29, rate time volume.


Four minutes with just pipe A and then unknown t minutes for pipes A and B together.

highlight%28highlight%2825%2A4%2B65%2At=100%29%29
Solve for t.
The outlined equation is the most important part of the solution.