From the above table,
For per litre petrol, old price $$=Rs.\ 45.62$$ and
New price $$=Rs.\ 40.60$$
Decrement in price $$=Rs.\ 45.62 - Rs.\ 40.62 =Rs.\ 5$$
So, Decrease percentage $$=\dfrac{4}{45.62} \times 100 =10.96 \%$$
For per litre diesel, old price $$=Rs.\ 32.86$$ and
New price $$Rs.\ 30.86$$
Decrement in price $$=Rs.\ 32.86 - Rs.\ 30.86=Rs.\ 2$$
So, Decrease percentage $$=\dfrac{2}{32.86} \times 100 =6.09 \%$$
For LPG, old price $$Rs.\ 304.70$$ and New price $$Rs.\ 279.70$$
Decrement in price $$=Rs.\ 304.70 - Rs.\ 279.70=Rs.\ 25$$
So, Decrease percentage $$=\dfrac{25}{304.70} \times 100 =8.20 \%$$