The price of oil is increased by 25\%. If the expenditure is not allowed to increase, the ratio between the reduction in consumption and the original consumption is
(a)1: 3
(b)1: 4
(c)1: 5
(d)1: 6
Answer
Answer (as printed): C
Explanation
Let original consumption be 1 unit costing ₹ 100. $$\begin{aligned} & \text { New cost }=₹ 125 . \text { New consumption }=\left(\frac{1}{125} \times 100\right)=\frac{4}{5} \text { unit. } \\ & \therefore \frac{\text { Reduction in consumption }}{\text { Original consumption }}=\frac{\left(1-\frac{4}{5}\right)}{1}=\frac{1}{5}, \text { i.e., } 1: 5 . \end{aligned}$$
Explanation as extracted from the printed page; notation may be imperfect.