Subject: General Aptitude · Chapter: Average · Exam: · Marks: · Difficulty:
A car owner buys petrol at ₹ 17, ₹ 19 and ₹ 20 per litre for three consecutive years. Compute the average cost per litre, if he spends ₹ 6460 per year.
(a)₹ 18.49
(b)₹ 18.58
(c)₹ 19.2
(d)₹ 21.66
Answer
Answer (as printed): B
Explanation
Total quantity of petrol consumed in 3 years $$\begin{aligned} & =\left(\frac{6460}{17}+\frac{6460}{19}+\frac{6460}{20}\right) \text { litres } \\ & =(380+340+323) \text { litres }=1043 \text { litres. } \end{aligned}$$ Total amount spent $=₹(3 \times 6460)=₹ 19380$. $$\text { ∴ Average cost }=₹\left(\frac{19380}{1043}\right)=₹ 18.58 .$$
Explanation as extracted from the printed page; notation may be imperfect.