An aqueous solution with NaOH 10 g/L at the rate is 100 L/min and an organic compound with no NaOH at the rate 50 L/min were put into an extraction machine and produced aqueous solution with NaOH 1 g/L, what is the amount of NaOH in organic compound after extraction?

Correct Answer: 9 g/L
NaOH balance equation, 100(10) + 50(0) = 100(1) + 50(x).