Question

The sale of a particular item has decreased by 20%.by what percent price of the item should be increased so that there is no change in revenue collection a) 15% b) 20% c) ( 45 / 2 ) % d) 25%

Answer 1

Solution:-
Let the sales of the particular item be 'x', price of that item be 'y' and the collection be 'r'.
Then, r = x × y  .......(1)
The sales of the item is decreased by 20 %, so the new sales is given by,
x1 = x - (x*20)/100
⇒ x/1 - x/5
⇒ x1 = 4x/5
New price be 'y1'.
r = x1 × y1
Putting the value of r = x × y and x1 = 4x/5 in above, we get
⇒ x × y = 4x/5 × y1
⇒ x × y × 5/4x = y1
⇒ y1 = 5y/4
Increase in price = New price - old price
⇒ 5y/4 - y
⇒ increase in price = y/4
So, the percentage of increase in price = {(y/4) × (100)}/y
⇒ 100/4
⇒ 25 %
So, the price of the item should be increased by 25 %, so that there is no change in revenue collection.
The option (d) is correct.

Answer 2

Step-by-step explanation:

the answer must be 20/100+20=25%