Question

the price of notebook increased by x% to bring the price of earlier level it had to be reduce by 50/3%.find the value of x

Answer 1

Let's understand this by Percentage change Graph (PCG).

100 -----(increase by 25%)----> 125 --------(decrease by 20%)-------> 100

Note: Change in % = ( (Final - Initial) / Initial) * 100 %

1st Case: ((125-100)/100) * 100% = 25 % (positive value, hence increase)

2nd case: ((100 -125)/125) * 100 % = -20 % (negative value, hence 20% decrease)

Your case:

100 ----(some % increase)---> Z -----(decrease by 16.66%)----> 100

First, You need to find what number drops by 16.66 % to become 100, i.e. value of Z.

Therefore, ((100-Z)/100) * 100 % = -16.66. Solve this, you will get, Z = 120.

Now, the situation is,

100 ------(increase by some %)-----> 120

Definitely, it's 20%

Explore the PCG. Look at the pic!

Answer 2

(100 + x) – (100 + x/100) x (50/3) = 100

(100 + x) [ 1 – 50/300 ] = 100

(100 + x) [ 300 – 50/300 ] = 100

(100 + x) [ 250/300 ] = 100

(100 + x) = 100 x 300/250

(100 + x) = 30000/250

(100 + x) = 120

x = 120 – 100

x = 20

Hence, The value of x = 20 or 20% Increase was made to the initial price.