A car owner buys petrol at Rs.7.50, Rs. 8 and Rs. 8.50 per litre for three successive years. What approximately is the average cost per litre of petrol if he spends Rs. 4000 each year?

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Question: A car owner buys petrol at Rs.7.50, Rs. 8 and Rs. 8.50 per litre for three successive years. What approximately is the average cost per litre of petrol if he spends Rs. 4000 each year?
[A].

Rs. 7.98

[B].

Rs. 8

[C].

Rs. 8.50

[D].

Rs. 9

Answer: Option A

Explanation:

Total quantity of petrol
consumed in 3 years
= 4000 + 4000 + 4000  litres
7.50 8 8.50
= 4000 2 + 1 + 2  litres
15 8 17
= 76700  litres
51

Total amount spent = Rs. (3 x 4000) = Rs. 12000.

Average cost = Rs. 12000 x 51 = Rs. 6120   = Rs. 7.98
76700 767