Question

A 40% sugar solution is added to an 85% sugar solution to create 1800 mL of a 60% solution. How much of each solution is used? (Use either elimination or substitutions) SHOW ALL STEPS PRETTY PLEASE !!

Answer 1

Number of ml of 40% sugar = x = 1000mL

Number of ml of 85% sugar used = y = 800mL

Explanation:

Let the

Number of ml of 40% sugar = x

Number of ml of 85% sugar used = y

From the above question, our system of equations is given as:

x + y = 1800mL ....... Equation 1

x = 1800 - y

40% × x + 85% × y = 60% × 1800mL

0.4x + 0.85y = 1080.... Equation 2

We substitute 1800 - y for x in Equation 2

0.4(1800 - y) + 0.85y = 1080

720 - 0.4y + 0.85y = 1080

- 0.4y + 0.85y = 1080 - 720

0.45y = 360

y = 360/0.45

y = 800mL

Solving for x

x = 1800 - y

x = 1800 - 800

x = 1000mL

Therefore,

Number of ml of 40% sugar = x = 1000mL

Number of ml of 85% sugar used = y = 800mL