The marked price of an article is increased by 25% and the selling price is increased by 16.66%

Ques - The marked price of an article is increased by 25% and the selling price is increased by 16.66%, then the amount of profit doubles. If the original marked price be Rs. 400 which is greater than the corresponding cost price by 33.33%, what is the increased selling price ?

(a) 240

(b) 360

(c) 420

(d) 600

Solution -

Original marked price = 400

Increased MP = 400 × (125 / 100)

= 500

Let,

The CP = x

Original MP = x + (x × 33.33%)

400 = x + x × (1/3) 

400 = 4x/3

x = 300

So,

CP = 300

Let,

The original profit = y

Original SP = CP + profit

Original SP = 300 + y

New SP = (300 + y) + (300 + y) × 16.66%

= (300 + y) + (300 + y) × (1/6)

= (1800 + 6y + 300 + y) / 6

= (2100 + 7y) / 6

New profit = 2y

New profit = SP - CP

2y = [(2100 + 7y) / 6] - 300

6 (2y + 300) = 2100 + 7y

12y + 1800 = 2100 + 7y

12y - 7y = 2100 - 1800

5y = 300

y = 60 

Original profit = 60

New profit = 2y

= 2 × 60

= 120

New SP = CP + New profit 

New SP = 300 + 120

= 420

Therefore,

The increased Selling price is Rs. 420.

Hence,

The correct answer is option (c) 420.

Thank You