A tea seller used to make 50% of profit by selling tea at ₹9 per cup. When the cost of ingredients increased by 25%, he started selling tea at ₹10 per cup. What is his profit percentage now?

$33\frac{1}{3}$

+50% = \(\frac{3x}{2x}\) = \(\frac{9}{6}\) = \(\frac{SP}{CP}\)

         CP                  SP

         6                    9

When the cost price increased by 25%

         CP                  SP

         7.5                 10

Profit = 10 - 7.5 = 2.5

Profit % =  \(\frac{2.5 × 100}{7.5}\) = $33\frac{1}{3}$