TIP-2

If the price of the comodity is increased or decreased by r% then reduction in the consuption so as not to increase the expenditure :

(

r

100+ r

) x 100

Example 1:  If the price of the sugar fall down by 10%. By how much percent must the householder increase its consuption so as not to decrease the expenditure.

solution:

increase in consuption :

10

100 - 10

 x 100 = 11.11%

Example 2: If A's salary is 25% more than B then how much percent the B's salary is less than that of A.

Solution:

B's salary is less than that of A :

25

100+ 25

 x 100 = 20%

Example 3:

 If A's salary is 30% less than that of B then how much percent is B's salary is more than that of A

Solution:

B's salary is more than that of A:

30

100 - 30

 x 100 = 42%

Example 4:

If the price of petrol is increased by 30 percent, by how much petrol a car owner must reduce his consumption in order to maintain the same budget.

Solution:

reduction in consumption :

30

100 + 30

 x 100 = 300/13%