A wrist watch is sold for ₹1,200 at a profit per cent equal to its cost price. Find the cost price of the wrist watch.
Answer & explanation
Correct answer: option 4
Let the cost price = x
Profit = x%
ATQ,
Cost price + profit = Selling price
x + \(\frac{x × x}{100}\) = 1200
x2 + 100x - 120000 = 0
x2 + 400x - 300x - 120000 = 0
(x + 400) (x - 300) = 0
x = 300