Weighted averages and mixtures
Grade 9 Math Worksheet

Circle the best answer.
Ari mixes 12 L of 15% juice with x L of 45% juice to make a 25% blend. How many liters x of the 45% juice are needed?
- 6 L
- 18 L
- 24 L
- about 2.7 L
Pia mixes 12 L of 20% syrup with x L of 70% syrup to make a 30% blend. How many liters x of the 70% syrup are needed?
- about 1.7 L
- 48 L
- 15 L
- 3 L
Noah mixes 9 L of 10% green paint with x L of 40% green paint to make a 20% blend. How many liters x of the 40% paint are needed?
- 13.5 L
- 18 L
- 4.5 L
- 2.25 L
Tala mixes 20 mL of 5% salt water with x mL of 35% salt water to make a 15% blend. How many milliliters x of the 35% water are needed?
- 30 mL
- about 5.7 mL
- 40 mL
- 10 mL
Pia needs 20 L of 26% solution from 20% stock and 50% stock. How many liters of the 50% stock?
- 5.2 L
- 4 L
- 16 L
- 10 L
Bo needs 12 kg of nut mix worth $5 per kg, made from $4 nuts and $7 nuts. How many kg of the $7 nuts?
- $60
- 4 kg
- 6 kg
- 8 kg
Zee needs 40 mL of 18% solution from 10% stock and 30% stock. How many mL of the 30% stock?
- 24 mL
- 20 mL
- 16 mL
- 7.2 mL
Current work 70%, final exam 30%. Current work average: 88. Ren wants a final grade of 90. What final exam score is needed, and is it possible (scores top out at 100)?
- Possible: the final needs to be about 94.7.
- Possible: a final score of 28.4 works.
- Possible: a final score of about 90.9 works.
- Possible: a final score of 92 works.
Skills 30%, quizzes 30%, final 40%. Skills: 84. Quizzes: 92. Luz wants a final grade of 90. What final score is needed, and is it possible (scores top out at 100)?
- Possible: the final needs to be 93.
- Possible: a final score of 94 works.
- Possible: a final score of 96 works.
- Possible: a final score of 37.2 works.
Projects 60%, exam 40%. Projects average: 85. Tala wants a final grade of 92. What exam score is needed, and is it possible (scores top out at 100)?
- Not possible: the exam would need to be 102.5.
- Possible: an exam score of 41 works.
- Possible: an exam score of 99 works.
- Possible: an exam score of about 96.7 works.

