A fruit seller purchased 300 bananas at the rate of ₹18 per dozen and sold 200 bananas at the rate of ₹24 per dozen and the remaining bananas at the rate of ₹21 per dozen. What is his net profit percentage?

$27\frac{7}{9}$

Given =

CP of 300 bananas = \(\frac{300}{12}\) or 25 Dozen = 25 × 18 = Rs.450

SP of 300 bananas = \(\frac{200}{12}\) or \(\frac{50}{3}\) Dozen = \(\frac{50}{3}\) × 24 = Rs.400

SP of 100 bananas= \(\frac{100}{12}\) or \(\frac{25}{3}\) Dozen = \(\frac{25}{3}\) 21 = Rs.175

Profit = SP - CP =  ((400+175) - 450) = 125

Profit% = \(\frac{125 × 100}{450}\)  = 27\(\frac{7}{9}\) %