wikiHow Cross Multiplication Practice Problems 1. Solve for x: 3/5 = 6/x 2. Solve for x: 2/3 = 10/x 3. Solve for x: 5/8 = 15/x 4. Solve for x: 4/7 = 12/x 5. Solve for x: 1/4 = 5/x 6. Solve for x: 2/9 = 14/x 7. Solve for x: 3/8 = 9/x 8. Solve for x: 5/6 = 15/x 9. Solve for x: 1/2 = 12/x 10. Solve for x: 7/9 = 28/x 11. A car travels 150 miles in 3 hours. What is its average speed in miles per hour? 12. If 15 workers can complete a project in 24 days, how many days would it take for 20 workers to complete the same project? 13. A can complete a job in 8 hours, while B can complete the same job in 12 hours. How long would it take for A and B to complete the job together? 14. A recipe calls for 2/3 cup of flour to make 12 cookies. How much flour is needed to make 30 cookies? 15. A contractor can complete a project in 16 days, while his assistant can complete the same project in 20 days. How long would it take for them to complete the project together? 16. A train travels 300 miles in 5 hours. What is its average speed in miles per hour? 17. A contractor can complete a project in 30 days, while his assistant can complete the same project in 40 days. How long would it take for the assistant to complete the project alone? 18. A water tank can be filled in 4 hours by a pipe, and drained in 6 hours by another pipe. If both pipes are opened together, how long would it take to fill the tank? 19. If 18 workers can complete a project in 10 days, how many workers are needed to complete the same project in 6 days? 20. A car can travel 75 miles on 3 gallons of gas. How many miles can the car travel on 6 gallons of gas? Page