<PRE><B>Question 1207199</B>
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Umbrellas? or pairs of socks?&lt;br&gt;
Tumi? or Sal?&lt;br&gt;
I can&#39;t imagine how you would be so careless as to post a question the way you did....&lt;br&gt;
But the meaning is clear: there are two types of items, costing R45 and R30 each; and there are a total of 16 items with a total cost of R585.&lt;br&gt;
The setup for a formal algebraic solution would look something like this:&lt;br&gt;
c = # of items of type 
d = # of items of type d&lt;br&gt;
c+d = 16  [the total number of items is 16]
45c+30d = 585  [the total cost is 585]&lt;br&gt;
Multiply the first equation by 30...
30c+30d = 480&lt;br&gt;
... and find the difference between that result and the second equation:&lt;br&gt;
15c = 105
c = 7&lt;br&gt;
ANSWER: c = 7 of type c and 16-7 = 9 of type d&lt;br&gt;
CHECK: 7(45)+9(30) = 315+270 = 585&lt;br&gt;
A quick, informal mental solution -- using exactly the same calculations -- can be obtained using logical reasoning:&lt;br&gt;
If all 16 items were type c, the total cost would be 16(30) = 480
The actual total cost is 585, which is 105 higher
The difference in cost between type c and type d is 15
The number of items of the higher-priced type is 105/15 = 7.&lt;br&gt;
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