Half of all visitors to a library have a library card, of the visitors to the library, 20% use the computers at the library. What is the probability that a visitor, selected at random, has a library card and uses a computer at the library?

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

Need ! the total ticket sales for a high school basketball game were $2,260. the ticket price for students were $2.25 less than the adult ticket price. the number of adult tickets sold was 230, and the number of student tickets sold was 180. what was the price of an adult ticket?

The ratio of the perimeters of two similar triangles is 4: 3. what are the areas of these triangles if the sum of their areas is 130cm2?