V (cone) = (1÷3) × (r×r×h) л cm3
3 cone = 1 cylinder (if "h" and "r" is same)
There is two cone...
1st one: (1÷3) × 3×3×5 л cm3 = 15л cm3
2nd one: (1÷3) × 3×3×8 л cm3 = 24л cm3
15 + 24 = 39л cm3
Answer:
7.5 L of 10% solution and 22.5 L of 30% solution
Step-by-step explanation:
Volume of 10% solution plus volume of 30% solution = total volume of 25% volume.
x + y = 30
Acid in 10% solution plus acid in 30% solution = total acid in 25% solution.
0.10 x + 0.30 y = 30 × 0.25
0.10 x + 0.30 y = 7.5
Solve the system of equations, using either substitution or elimination. I'll use substitution:
x = 30 − y
0.10 (30 − y) + 0.30 y = 7.5
3 − 0.10 y + 0.30 y = 7.5
0.20 y = 4.5
y = 22.5
x = 30 − y
x = 7.5
Sarah needs 7.5 L of 10% solution and 22.5 L of 30% solution.
