A woman sold her earphone for ₹2,000 and got a percentage profit equal to the numerical value of cost price. The cost price of the earphone is:
Answer & explanation
Correct answer: option 4
Let the cost price = x
then profit will be = \(\frac{x × x}{100}\) = \(\frac{x^2}{100}\)
x + \(\frac{x^2}{100}\) = 2000
x + \(\frac{x^2}{100}\) - 2000 = 0
x2 + 100x - 200000 = 0
x = 400