Question

The price of a laptop increased successively by 20% and 30%. if it finally costs rs 468, find its initial value?

Answer 1

Solution :-

Let the initial price of the laptop be Rs. x

Then, according to the question.

The price of the laptop is increased by 20 % 

⇒ x + (x*20)/100

⇒ x + 20x/100

⇒ x/1 + x/5

Taking LCM of the denominators and then solving it.

⇒ (5x + x)/5

⇒ Rs. 6x/5 

So, the price of the laptop is Rs. 6x/5 after 20 % increase.

Now, price is increased by 30 %

⇒ 6x/5 + (6x/5)*(30/100)

⇒ 6x/5 + 180x/500

⇒ 6x/5 + 9x/25

Taking LCM of the denominators and then solving it.

⇒ (30x + 9x)/25

⇒ 39x/25

Now, after successive price increase of 20 % and 30 %, the final cost price of the laptop is Rs. 468.

⇒ 39x/25 = 468

⇒ 39x = 468*25

⇒ x = 11700/39

⇒ x = 300

So, the initial price of the laptop is Rs. 300

Answer.

Answer 2

Let the intial value of a laptop= ₹ P

R1=20%, R2= 30%

Final value of a laptop(A)= ₹468

A= P(1+R1/100) ( 1+R2/100)

468 = P (1+20/100)(1+30/100)

468 = P(1+1/5) (1+3/10)

468 = P(6/5) (13/10)

468 = P (3×13/5×5)

468 = P × 39/25

P = 468 × 25/39

P= 12×25

P= 300

Hence, the intial value of laptop is ₹300.

==================================================================

Hope this will help you.....