A man purchased 7 bags of rice at the rate of Rs. 800 each, 8 bags of rice at Rs. 1000 each and 5 bags of rice at the rate of Rs. 1200 each. What is the average cost of one bag of rice ?

Correct Answer: Rs. 980
According to the question,
Average
= $$\frac{7 × 800 + 8 × 1000 + 5 × 1200}{20}$$
= $$\frac{5600 + 8000 + 6000}{20}$$
= $$\frac{19600}{20}$$
∴ Average = Rs. 980