A shopkeeper earns 10% on an investment but loses 20% on another investment. If the ratio of the two investments is 2 : 3, then the combined loss percentage is:

12%

Since, ratio of two investment = 2 : 3

Let the two investment be Rs. 20 and Rs.30 respectively.

Initial total investment = 20 + 30 = Rs. 50

∴ Investment after 10% gain = Rs. 22

Similarly, Investment after 20% loss = Rs. 24

Total investment after the gain and loss = 22 + 24 = 56.

Total gain = 56 – 50 = Rs. 6

Gain% = \(\frac{Gain}{Initial\;Amount}\) × 100 = \(\frac{6}{50}\) × 100 = 12%