Question

1. white chocolate costs $2.00 per bar, and dark chocolate costs $2.50 per bar. if you buy 15 bars of chocolate for $34 dollars, how many bars of dark chocolate did you buy?

Explanation:

Step1: Define variables

Let \( x \) be the number of dark chocolate bars, and \( y \) be the number of white chocolate bars. We know two equations: \( x + y = 15 \) (total number of bars) and \( 2.5x + 2y = 34 \) (total cost). From the first equation, we can express \( y = 15 - x \).

Step2: Substitute and solve

Substitute \( y = 15 - x \) into the cost equation: \( 2.5x + 2(15 - x) = 34 \). Expand it: \( 2.5x + 30 - 2x = 34 \). Combine like terms: \( 0.5x + 30 = 34 \). Subtract 30 from both sides: \( 0.5x = 4 \). Multiply both sides by 2: \( x = 8 \).

Answer:

8