Question

Two friends visited a taffy shop. Helen bought 3 kilograms of strawberry taffy and 1 kilogram of banana taffy for $18. Next, Julie bought 2 kilograms of strawberry taffy and 4 kilograms of banana taffy for $32. How much does the candy cost?

Answer 1

Each Kg of Strawberry Taffy costs $4, and each Kg of Banana Taffy costs $6.

Explanation:

Let s represent the strawberry taffy, and b represent the banana taffy.

We can solve this using a system of equations.
{3s+1b=18
{2s+4b=32

Using either substitution or elimination, we can solve this.
Substitution:

By moving 3s to 18, you get b = -3s+18

Substitute into the second equation

2s+4(-3s+18)=32

2s-12s+72=32

-10s+72=32

-10s=-40

s=4

So each Kg of Strawberry Taffy is $4. When you substitute 4 into s, you get 12+1b=18, which gets you b=6

Finally, each Kg of Strawberry Taffy costs $4, and each Kg of Banana Taffy costs $6.

Elimination:

{3s+1b=18
{2s+4b=32

{12s+4b=72

{2s+4b=32

Subtracting will give you 10s=40, which will get you s=4

So each Kg of Strawberry Taffy is $4. When you substitute 4 into s, you get 12+1b=18, which gets you b=6

Finally, each Kg of Strawberry Taffy costs $4, and each Kg of Banana Taffy costs $6.