A supermarket charges $4.50 for eight cans of cat food, at the same rate how much would 28 cans of cat food cost?

Question

$4.50*8=36.00, 36.00*8=

Answer 1

You have to obtain the unit value per can which is

4.50/8

Then obtain the value for the 28

(4.5/8)*28 = 15.75

Answer 2

Catherine,

 

You need to find the price for (8 + 8 + 8 + 4) = 28 cans of cat food.

 

This works out to (3 x $4.50) + 4 x ($4.50/8) = (3 x $4.50) + ($4.50/2) = $13.50 + $2.25 = $15.75

Answer 3

The $4.50 is for all 8 cans of cat food, so the cost for each can is:

 

$4.50/8 = $0.5625 per can    [56.25 cents per can)

 

So for 28 cans:

 

($0.5625 per can)*(28 cans) = $15.75

 

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Another way to do it is to set up a proportion:

 

$4.50/8 = $x/28

 

Solve for x - same answer as above.