Question

I spend Rs.3300 per month at a nearby mall. However, this month the prices of all the items
were hiked by 10%. What percent reduction in my consumption will help me keep my budget
Constant.

Answer 1

Given:

The prices of all the items  were hiked by 10%

To find:

What percent reduction in consumption will help me keep the budget  constant.

Solution:

Let us consider the actual price of the items in 100 units.

Then the actual consumption will be X

It is given in the question that the price of the item is increased by 10%

so the new price will be 110 units.

Let the new consumption will be Y

Here the expenditure must be kept the same so we get:

100X = 110Y

X/Y = 110/100

Consumption is decreased by 10 units over 110

so we get:

Percentage change in consumption = $\frac{10}{110}.100$

Change = 1/11

Change = 9.99%

So the consumption must be decreased by 9.99% to keep the expenditure constant.

Answer 2

Answer:

it's actually 9.09%

Step-by-step explanation:

Percentage change in consumption = \frac{10}{110}.100

110

10

.100

Change = 1/11

Change = 9.09%