Question

The Everton College store paid $2044 for an order of 52 calculators. The store paid $11 for each

scientific calculator. The others, all graphing calculators, cost the store $57 each. How many of each type
of calculator was ordered?
The store ordered __ scientific calculators and __ graphing calculators.

Answer 1

The Everton College store bought 20 Scientific and 32 Graphing Calculators.

Explanation:

Let S and G stand for the numbers of Scientific and Graphing calculators, respectively.

We know the total of S+G = 52 [an order of 52 calculators.]

S+G=52

We can calculate the total cost by summing the costs for both calculator types:

Scientific = 11S

Graphing = 57G

$2044 = 11S+57G [store paid $2044 for an order of 52 calculators]

11S+57G=2044 [Reorganize]

Now take either equation and isolate one of the variables. Let's choose the first equation and isolate the S:

S=52-G

Now use this expression for S in the second equation (substitute):

11S+57G=2044

11(52-G)+57G=2044

572-11G+57G=2044 [Expand and combine like terms]

46G = 1472

G = 32 [32 Graphing calculators were bought by the store]

Now find S using the first equation:

S+G=52

S+32 =52

S=20 [20 Scientific calculators were bought]

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Check:

1) Do 32 and 20 equal a total of 52 calculators? YES

2) Do these numbers of calculators add up to a total cost of $2044?

S: $11*(20)=$220, and

G: $57*(32) = $1824

Total = $2044 YES

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The Everton College store bought 20 Scientific and 32 Graphing Calculators.