A man wishes to sell a puppy for $11. A customer wants to buy it but only has foreign currency. The exchange rate for the foreign currency is 11 round coins = $15, 11 square coins = $16, 11 triangular coins = $17.

How many of each coinage should the customer pay?

set it up as a matrix equation:
[11 0 0]-1 [15]
[0 11 0] (*) [16]
[0 0 11] [17]

put in calculator (TI 83) under matrix a and matrix b:

find the inverse of matrix a and multiply it by matrix b and you'll get your answer! enjoy!

Posted by Ness on 2003-11-01 16:38:58