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Question

20kg of radish and 8kg of capsicum cost $87 whereas 16kg of radish and 5kg of capsicum cost $66.52. Find the cost of 1kg of each item.

Answer 1

Hi Amy,

 

Let's let

r = cost of a kg of radishes

c = cost of a kg of capsicum

 

We knpw

20r + 8c = 87

16r + 5c = 66.52

 

Let's multiply the first equation by 5 and the second equation by -8.

 

(20r + 8c = 87)5
(16r + 5c = 66.52)(-8)

 

This gives us

100r + 40c = 435

-128r - 40c = -532.16

 

Now add these two equations together.

-28r = -97.16

r = 3.47

If 20r + 8c = 87

then 20(3.47) + 8c = 87

c = 2.20

 

Radishes cost $3.47 per kg

Capsicum is $2.20 per kg