<PRE><B>Question 677573</B>
12. The average of x numbers is 15.
 If two of the numbers are each increased by y, the new average will be increased by how much?
:
We can write the original average as (for understanding purposes):
{{{(15x)/x}}} = 15 average
:
We add y to two of the numbers and we have
{{{(15x+2y)/x}}} = the new average
:
The difference between the two averages
{{{(15x+2y)/x}}} - 15
we can write it as two fractions
{{{(15x)/x}}} + {{{(2y)/x}}} - 15
Cancel x, 15 is eliminated
15 + {{{(2y)/x}}} - 15 = {{{2y/x}}} is the increase in average</PRE>