1. 10.8 Mixture Problems Goal: To solve problems involving the mixture of substances

2. Mixture Problems One solution is 80% acid and another is 30% acid. How much of each is required to make 200 L of solution that is 62% acid?

3. Steps to Solve Mixture Problems • Set up a chart (4x4)

4. Steps to Solve Mixture Problems • Convert the percentages to decimals and fill out the chart • Multiply going across the chart • Add going down the chart • Set up 2 equations with 2 variables (system) • Solve the system by substitution or addition

5. Let x = y = x 0.80 .80(x) One solution is 80% acid and another is 30% acid. How much of each is required to make 200 L of solution that is 62% acid? y 0.30 .30(y) .62(200) 200 0.62 124

6. 8x + 3y =1240 Y= 200-x 8x + 3 (200-x) =1240 Y = 200 -128 8x +600 -3x =1240 x 0.80 .80(x) One solution is 80% acid and another is 30% acid. How much of each is required to make 200 L of solution that is 62% acid? 5x +600 =1240 Y = 72 L 5x = 640 y 0.30 .30(y) X= 128 L .62(200) 200 0.62 124

7. x 0.60 .60(x) A chemist has one solution that is 60% acid and another that is 30% acid. How much of each solution is needed to make a 750ml solution that is 50% acid? y 0.30 .30(y) .50(750) 750 0.50 375

8. x 0.28 .28(x) A chemist has one solution that is 28% oil and another that is 40% oil. How much of each solution is needed to make a 300 L solution that is 36% oil? y 0.40 .4(y) .36(300) 300 0.36 108

9. Try to make your own chart • How many gallons of a 50% salt solution must be mixed with 60 gallons of a 15% solution to obtain a solution that is 40% salt?

10. How many gallons of a 50% salt solution must be mixed with 60 gallons of a 15% solution to obtain a solution that is 40% salt?

11. System x + 60 =y 0 .5x + 9 = 0.4y 5x +90 = 4y 5x + 90 = 4 (x +60) 5x + 90 = 4x + 240 x + 90 =240 x =150 gallons 150 + 60 = y 210 gallons =y

12. Coffee Beans • How many pounds of coffee beans selling for $2.20 per pound should be mixed with 2 pounds of coffee beans selling for $1.40 per pound to obtain a mixture selling for $2.04 per pound?

13. How many pounds of coffee beans selling for $2.20 per pound should be mixed with 2 pounds of coffee beans selling for $1.40 per pound to obtain a mixture selling for $2.04 per pound?

14. System X + 2 =y 2.20x +2.80 = 2.04 y

16. Your Turn • Come up with your own mixture word problem. Make it interesting! • Remember to include:

17. Assignment:Page 462 (1 -9) odd

19. 1 .20 .20 x .00 .00(x) .20 x+1 .06

20. Vocabulary • Mixture- two substances combined • Concentrate or Solution- how much non-water is mixed (juice) • 10% solution -10% concentration and 90% water