**Concept: The question tests on the basics of average/mixture**

**Solution:**

By the rule of alligations, Q1/Q2=P2−P/ P-P−1

Where Q1 and Q2 are the quantities of the cheaper and costlier rice

P1 and P2 are their Prices and P is the average price.

Q1/Q2=10.8−10/10−9.30=0.8/0.7=8/7**Option C**