Question

A snack shop sells peanuts at $1.30 per pound and chocolate chips at $1.90 per pound. The owner decided to make a ten pound mixture of the two and sell it for $1.42 a pound. How many pounds of peanuts should be in the mixture

Answer 1

8 pounds of peanuts

Explanation:

In this case we can solve it using a 2x2 system of equations, like this:

let x be pounds of peanuts

let y be pounds of chocolate chips

So:

1.3 * x + 1.9 * y = 1.42 * 10

x + y = 10 => x = 10 - y

Replacing, we are left with that:

1.3 * (10 - y) + 1.9 * y = 1.42 * 10

13 - 1.3 * y + 1.9 * y = 14.2

1.9 * y - 1.3 * y = 14.2 - 13

0.6 * y = 1.2

y = 1.2 / 0.6

y = 2

Now to calculate x:

x = 10 - 2

x = 8

Which means they are 8 pounds of peanuts and 2 pounds of chocolate chips.