Question

a store allows costumers to fill their own bags of candy, Terri decides she only wants jelly beans and chocolate drops, jelly beans sell for $0.98 per pound, and chocolate drops sell for $0.67 per pound, Terri's bag weighs 2.1 pounds and its costs $1.56. How many pounds of jelly beans and chocolate drops did Terri buy?

Answer 1

Use a system of equations!

We know that:

$1.56 = 0.98j + 0.67c

(j represents how many pounds of jelly beans, and c represents how many pounds of chocolate drops)

We also know that:

2.1 = c + j

(Because the amount of jelly beans and chocolate chips together should be 2.1 pounds)

So, we can rearrange the second equation to get:

c = 2.1 - j

then plug that into the original equation we made:

1.56 = 0.98j + 0.67(2.1 - j)

Then use our algebra skills to solve for j, giving us:

j = 153/310 = about 0.494

now plug j into the "c = 2.1 - j" equation and solve for c algebraically:

c = 249/155 = about 1.606

So, that means it costs about $0.49 for one pound of jelly beans, and about $1.61 for one pound of chocolate drops.

We can check that it's correct by plugging our values of c and j into our first equation:

1.56 = 0.98j + 0.67c
1.56 ~ 0.98(0.49) + 0.67(1.61)
1.56 ~ 0.4802 + 1.0787
1.56 ~ 1.5589