Question 957603
Nine man went to a hotel.  Eight of them spent rs 10 each on their meals. The
ninth man spent rs 4 more than the average of all of them. How much did the
ninth man spend?
<pre>
The first eight men spent rs 80 and the ninth man spent rs x. 

The sum that all 9 men spent was 80+x

The average of all nine men was rs {{{(80+x)/9}}}

The equation comes from this sentence:
</pre>
The ninth man spent rs 4 more than the average of all of them.
<pre>
{{{x}}}{{{""=""}}}{{{(80+x)/9}}}{{{""+""}}}{{{4}}}.

Clear of fractions by multiplying through by 9:

{{{9x}}}{{{""=""}}}{{{80+x}}}{{{""+""}}}{{{36}}}

{{{9x}}}{{{""=""}}}{{{116+x}}}

{{{8x}}}{{{""=""}}}{{{116}}}

{{{x}}}{{{""=""}}}{{{14.5}}}

Solution: rs 14.50

Average = {{{(10+10+10+10+10+10+10+10+14.5)/9}}} = {{{10.5}}}

The ninth man spent rs 14.5 and the others spent rs 10.  So
he spent rs 4 more than what the others spent.

Edwin</pre>