Question

If the price of an article is reduced by 20%, by what percent the consumption be increased to keep the expenditure unaltered ?

Answer 1

Let the initial expenditure on the article be Rs. 100.
Now, the price decreases by 20%,
Current Price = (100 - 20% of 100) = Rs. 80.
Current expenses on article = cost+consumption of current cost = (80 + x) = Rs. 100

x=20
x = 25 % of 80

so here consumption should be increased by 25% to keep the expenditure unaltered.