Question 689374
one pipe can fill a swimming pool in 10 hours. if a second pipe is used
together with the first pipe, the pool can be filled in 6 hours. how long would
it take the second pipe alone to fill the pool?
<pre>
We are given the first pipe's filling rate as 1 pool per 10 hours, or
{{{(1_POOL)/(10_HOURS)}}} or {{{1/10}}}{{{POOL/HR)}}}

We let X = the number of hours it takes ths second pipe to fill the pool.

So we can say the second pipe's filling rate is 1 pool per X hours, or
{{{(1_POOL)/(X_HOURS)}}} or {{{1/X}}}{{{POOL/HR)}}}.

We are given their combined filling rate as 1 pool per 6 hours, or
{{{(1_POOL)/(6_HOURS)}}} or {{{1/6}}}{{{POOL/HR)}}}.

The equation comes from:

      {{{(matrix(5,1,

The, first, "pipe's", filling, rate))}}}{{{""+""}}}{{{(matrix(5,1,

The, second, "pipe's", filling, rate))}}}{{{""=""}}}{{{(matrix(4,1,

Their, combined, filling, rate))}}}.

              {{{1/10}}}{{{""+""}}}{{{1/X}}}{{{""=""}}}{{{1/6}}}

Solve that by getting an LCD of 30X

Answer:  X = 15 hours.

Edwin</pre>