If price of oil is increased by 33¹/₃%, by how much a housewife must reduce consumption of oil so that her expenditure on oil remains the same?

If price of x amount oil was 100

Then, now it is 100+331/3 = 1331/3

Housewife used to spend 100 for x amount of oil.

1331/3  is the price of x amount

100 is the price of x*100/1331/3 

                            = x*100*3/400

                            = 3x/4

Must reduce (x- 3x/4)

                   = (4x-3x)/4

                   = x/4

    &nbs