Question

Mixed 3 liters 20% solutions with 2 liters 70% solution. What’s the final concentration,

Answer 1

(3×20%+2×70%)/3+2=40%

Explanation:

Assuming the potions are the same type or do mix then probably the concentration of the potion depends on the type of reaction they have to each other.

Yet we can average the percentage of the active ingredient by the principle mentioned above

Answer 2

The final concentration is 40%.

Explanation:

Let x the concentration of final solution.

3 liters of solution (1) with 20% concentration is mixed with 2 liters of 70% solution producing (3 + 2) = 5 liters of x% mixture.

Now 3 × (20%) + 2 × (70% = 5 (x%)

3 × 0.2 + 2 × 0.7 = 5 (0.1x)

0.6 + 1.4 = 0.05x

2 = 0.5x

x = 2/0.05

= 40%

The final concentration is 40%.