The price of sugar rise by 25%. If a family wants to keep ir expenses on sugar same as earlier, family will have to decrease its consumption of sugar by

Let the initial expenses on Sugar was Rs. 100.
Now, Price of Sugar rises 25%. So, to buy same amount of Sugar, they need to expense,
= (100 + 25% of 100) = Rs. 125.
But, They want to keep expenses on Sugar, so they have to cut Rs. 25 in the expenses to keep it to Rs. 100.
Now, % decrease in Consumption,
$$\frac{{25}}{{125}} \times 100 = 20\% $$

Mind Calculation Method;
100 === 25%↑ ===> → 125 === X%↓ ===> 100
Here, X = $$\frac{{25}}{{125}} \times 100 = 20\% $$