A 20% reduction in the unit cost of an article enables one to buy 25 items more for Rs.1000

Explanation:

Let the original unit cost of the item be = 100A

Then for Rs 1000 we can buy = 1000/100A = 10/A = articles.

If 20% reduction in the unit cost happen then the unit cost becomes

Now the number of articles one can buy with Rs = 1000/80A = 25/2A 1000

Final Answer:

Hence the correct option is C 10