How much would Mrs. Baker pay for 8 pounds of bananas?

[mathdad]

Mrs. Baker paid 2.50 for 5 pounds of bananas. Write an equation relating the cost c to the number of pounds p of bananas.How much would Mrs. Baker pay for 8 pounds of bananas?

My Work:

2.50/c = 5/8

5c = 2.50 • 8

5c = 20

c = 4 dollars

Equation:

The cost per pound is 2.50 ÷ 5 = 0.50.

C(p) = 0.50p

 

[Greg]

Looks good.

 

[mathdad]

This is so cool. I am interested in the set up.

 

[HallsofIvy]

You answered the second question, "How much would Mrs. Baker pay for 8 pounds of bananas?" but did not do the first, "Write an equation relating the cost c to the number of pounds p of bananas."

 

[I like Serena]

You answered the second question, "How much would Mrs. Baker pay for 8 pounds of bananas?" but did not do the first, "Write an equation relating the cost c to the number of pounds p of bananas."

Actually, RTCNTC did, just in reverse order.

Equation:

The cost per pound is 2.50 ÷ 5 = 0.50.

C(p) = 0.50p

We can actually now fill in the cost for 8 pounds of bananas:
$$C(8\text{ pounds}) = 0.50\frac{\text{£}}{\text{pound}} \cdot 8\text{ pounds} = 4\text{ £}$$
which agrees with the result RTCNTC found earlier.

 

[mathdad]

Thank you everyone.