A Car Owner Buys Petrol At Rs. 7.50, Rs. 8 And Rs. 8.50 Per Liter For Three Successive Years. What Approximately Is The Average Cost Per Liter Of Petrol If He Spends Rs. 4000 Each Year?

Question: A Car Owner Buys Petrol At Rs. 7.50, Rs. 8 And Rs. 8.50 Per Liter For Three Successive Years. What Approximately Is The Average Cost Per Liter Of Petrol If He Spends Rs. 4000 Each Year?
a. Rs. 7.98
b. Rs. 10.50
c. Rs. 12.50
d. Rs. 15