Sarah needs 30 liters of a 25% acid solution how many liters of the 10% and the 30% acid solutions should she mix to get what she needs

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.

Sarah needs 7.5 liters of the 10% acid solution and 22.5 liters of the 30% acid solution.

Step-by-step explanation:

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step-by-step explanation:

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126.66 m²

step-by-step explanation:

the pertinent area formula is a = πr², where r is the radius.

here, a = π(6.35 m)² = 40.32π, or approximately 126.66 m²