If the price of sugar is increased by 25% today, by what percent should it be decreased tomorrow to bring the price back to the original ?

Lets take today's price of sugar as ₹100.

The price of sugar is increased by 25%.

∴ Increased Price = 100 + 25% of 100

= $100 + \Big(\dfrac{25}{100} \times 100\Big)$

= $100 + \Big(\dfrac{1}{4} \times 100\Big)$

= $100 + \Big(\dfrac{100}{4}\Big)$

= $100 + 25$

= $₹125$

If new price is ₹125 and old price was ₹100, then we can say that new price is ₹25 more than the old price.

Percentage decrease = $\dfrac{\text{New price - old price}}{\text{new price}} \times 100$%

= $\dfrac{(125 - 100)}{125} \times 100$%

= $\dfrac{25}{125} \times 100$%

= $\dfrac{1}{5} \times 100$%

= $\dfrac{100}{5}$%

= 20%

Hence, price should be decreased 20% tomorrow to bring the price back to the original.