A milkman purchases milk at ₹'a' per litre and sells it at ₹1.5a per litre. Still he mixes 2 litres water with every 9 litres of pure milk. What is his profit percentage?

$\frac{250}{3}$ %

According to the question,

a to 1.5a means = cost is 2 and selling is 3

and mixes 2 litres water with every 9 litres of pure milk means cost is 9 ans selling is 11 so,

                      CP               SP

Price               2                  3

Quantity          9                11

                  ———————————

                    18                33

Profit% = ( 33 - 18) × $\frac{100}{18}$ = $\frac{250}{3}$ %