A reduction of 20% in the price of sugar enables a person to purchase 6 kg more for Rs. 240. What is the original price per kg of sugar?

Let the initial price of 100 kg Sugar was Rs. 100.
Now, a 20% decrease in rate then rate of 100 kg sugar would be Rs. 80.
So, Rs. 80 = 100 kg sugar.
Rs. 100 = 100× $$\ \ \frac{100}{80}$$ = 125 Kg sugar.
Increment in sugar = 25 kg.
% increment = $$\ \ \frac{125-100}{100}\times\ 100$$ = 25%.
25% increment = 6 kg of sugar

total sugar initially = 6*4 =24 kg

Original price of the sugar = $$\ \ \frac{240}{24}$$

= Rs. 10 per kg

A is the correct answer.