A. Rs. 7.98
B. Rs. 8.08
C. Rs. 8.98
D. Rs. 9.08
Total quantity of petrol consumed in three years is:
( 4000 / 7.5 ) + ( 4000 / 8 ) + ( 4000 / 8.5 )
=> 4000 ( 2/15 + 1/8 + 2/17 ) = 76700 / 51
=> Total amount spent = 3 x 4000 = Rs. 12000/-
=> So, Average Cost = 12000 / (76700/51) = ( 12000 x 51 ) / 76700 = Rs. 7.98/-