An article is sold at 20% profit. It its cost price is increased by 50 and at the same time if its selling price is also increased by 30, the percentage of profit decreases by then the cost price is

A. 851

B. 852

C. 850

D. 853

Correct Answer is :

C. 850

Explanation

Let initial cost price be x Rs. Profit = 20/100 * x = x/5 So selling price = x + x/5 = 6x/5 If cost price = x + 50 Selling Price = 6x/5 + 30 Profit = (6x/5 + 30) - (x + 50) = x/5 -20 Profit Percentage = (x/5 - 20) / (x + 50) * 100 But in according to the question profit percentage = 20 - 10/3 = 50/3 % So (x/5 - 20) / (x + 50) * 100 = 50/3 ∴ (x/5 - 20) / (x + 50) = 1/6 ∴ 6x/5 - 120 = x + 50 ∴ x/5 = 170 ∴ x = 850 So original cost price = Rs 850