Question

Six grapefruit cost as much as a dozen oranges. The cost of a dozen grapefruit and two dozen oranges

is $12. If Susan purchased one orange and one grapefruit, how much did she spend? Show your

thinking.


a.Write System of equations for the above problem.



b. Solve the system of equations


c.Explain the meaning of the solution in the context of the problem.

Answer 1

Answer:

$0.73

Step-by-step explanation:

Let's say an orange costs O dollars and a grapefuit costs G dollars.

We add G dollars for each grapefuit and O dollars for each orange, so, for example, 12 grapefuit = G added 12 times = 12 *G = 12G

a.

6G = 10O

12G + 24O = 12

6 grapefuit = 6G = 10 oranges = 10O

b.

6G = 10O

12G + 24O = 12

We can solve this using substitution. First, we can solve the first equation for G. After that, we can plug that into the second to find O and go from there.

6G = 10O

divide both sides by 6 to remove the coefficient for G

G = (10/6)O

plug that into the second equation

12*(10/6)O + 24O = 12

20O + 24O = 12

44O = 12

divide both sides by 44 to solve for O

O=12/44 = 6/22

6G = 10O

6G = 60/22

divide both sides by 6 to solve for G

10/22 = G

c.

These solutions mean that an orange (O) costs 6/22 dollars and a grapefuit (G) costs 10/22, so 1O + 1G = 16/22 dollars ≈ $0.73. Note that O and G are kept as fractions because they are not exact dollar amounts, e.g. 0.27 repreating