Suppose the cause of produce x toys is c(x) = 80x + 150 and the revenue by selling x such toys is r(x) = -1.5x² + 250x. Determine the number of toys needs to sell to make a positive profit.

A \( \left ( \frac{170 - 20 \sqrt{50}}{3} , \left ( 170 \right. \right. \)

B \( \left ( \frac{170 - 20 \sqrt{70}}{3} , \frac{170 + 20 \sqrt{70}}{3} \right ) \)

C \( \left ( \frac{150 - 20 \sqrt{70}}{3} , \frac{150 + 20 \sqrt{70}}{3} \right ) \)

D \( \left ( \frac{170 - 15 \sqrt{70}}{3} , \frac{170 + 15 \sqrt{70}}{3} \right ) \)

Correct Answer: Option B

Suppose the cause of produce x toys is c(x) = 80x + 150 and the revenue by selling x such toys is r(x) = -1.5x2 + 250x. Determine the number of toys needs to sell to make a positive profit.