Government announced that from tomorrow lockdown will start. Ram urgently needed a watch so he went to a shop to buy a watch. Shopkeeper sold him the watch for Rs.75 and earned percentage profit equal to the cost price. What is the cost price of the watch for the shopkeeper.

Government announced that from tomorrow lockdown will start. Ram urgently needed a watch so he went to a shop to buy a watch. Shopkeeper sold him the watch for Rs.75 and earned percentage profit equal to the cost price. What is the cost price of the watch for the shopkeeper. Correct Answer 50

Given:

Selling price of shopkeeper = 50

Formula used:

Profit% = Profit/cost price × 100

Profit % = (selling price – cost price)/cost price × 100

Calculations:

 Let the cost price for the shopkeeper be x.

Profit % = x%

⇒ 75 – x /x × 100 = x

⇒ x² + 100x – 7500 = 0

⇒ x² +150x – 50x – 7500 = 0

⇒ x (x - 50) + 100 (x – 50) = (x – 50) (x + 100)

⇒ x = 50 or -150

Cost Price can’t be negative.