77. An article is said to have been sold at the price of 830.4 dollars. Then it already earned a profit of 12% on the cost price. Solutions: => 830.4 dollars is the total costs of article including the 12% profit => 12% is the profit of the said article. => 12% = 12% / 100% = 0.12 => 830.4 * .12 = 99.648 = the value of profit Now, let’s subtract this to find the original cost => 830.4 – 99.648 = 730.752 = the original price of the article.