UGC NET Paper 1 GA 2012 June Solved Paper

Let the price of petrol be ₹ 100 per litre. Let the user use 1 litre of petrol. Therefore, his expense on petrol = 100 × 1 = ₹ 100
Now, the price of petrol increases by 25%
Therefore, the new price of petrol = ₹ 125.
As he has to maintain his expenditure on petrol constant, he will be spending only ₹ 100 on petrol.
Let ‘x’ be the number of litres of petrol he will use at the new price.
Therefore,
$125\times \mathit{x}=100$
$\Rightarrow \mathit{x}=\frac{100}{125}=\frac{4}{5}$ $=0.8$litre
He has cut down his petrol consumption by
0·2 litre $=\frac{0.2}{1}\times 100=20\%$