### 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. 8

**C.** Rs. 8.50

**D.** Rs. 9

## Show Answer

### Answer-A

Solution-

__Solution(By Apex Team)__

Total quantity of petrol consumed in 3 years $\begin{array}{l}=\left(\Large\frac{4000}{7.50}+\frac{4000}{8}+\frac{4000}{8.50}\ right)\text{L}\\ =4000\left(\Large\frac{2}{15}+\frac{1}{8}+\frac{2}{17}\right)\text{ litres } \\ =\Large\frac{76700}{51}\small\text{ liters }\\ \text{Total amount spent}\\=R s .(3 \times 4000)\\ =R s .12000\\ \therefore \text { Average Cost }\\ =R s . \Large\frac{12000 \times 51}{76700}\\ =R s . \Large\frac{6120}{767}\\ =R s .7 .98 \end{array}$