Briefly

Offers in the greengrocer

Offers in the greengrocer

In the market fruit stand, they have the following offers:

1kg of apples + 1kg of oranges cost € 4.30
1 kg of bananas + 1 kg of oranges cost € 3.70
1kg of apples + 1kg of bananas cost € 3.60

How much does a kilo of bananas cost?

Solution

If we define the following variables:
M = 1 Kg of Apples
P = 1 Kg of Bananas
N = 1 Kg of Oranges

We can rewrite the statement as follows:
M + N = 4.30
P + N = 3.70
M + P = 3.60

And clearing we get that
M = 4.30 - N
N = 3.70 - P
P = 3.60 - M

Where can we deduce
M = 4.30 - (3.70 - P) = 4.30 - (3.70 - (3.60 - M))

M = 4.30 - 3.70 + 3.60 - M

2M = 4.30 - 3.70 + 3.60 = 4.20

M = 2.10

Substituting in the third equation we obtain that
P = 3.60 - 2.10 = 1.50

And finally
N = 3.70 - 1.50 = 2.20.

M = 2.10
N = 2.20
P = 1.50

Thus the kilo of bananas costs € 1.50