Scientist A has invented a device for cars to save petrol by 20%. Scientist B's invention saves 30%. Invention of scientist C save 40%. The three inventions are independently in effect. If all three devices are used, how much petrol can one save?
Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.
Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.