1. A shipment contains x film cartridges for 15 exposures each and x + 10 cartridges for 25 exposures each. What is the total number of photographs that can be taken with the film from this shipment?

2. Each of two stores has 2n+ 1 mouse pads costing $3 each and n-2 pads costing $2 each. How much more is the total value of the $3 mouse pads than the $2 mouse pads in the two stores.

3. A person 1.8 m tall is photographed with a 35-mm camera, and the film image is 20mm. Under the same conditions, how tall is a person whose film image is 16mm?

4. In testing the rate at which a polluted stream flows, a boat travels at 5.5 mi/h in still water took 5.0 h to go downstream between points, and it took 8.0 h to go upstream between the same two points. What is the rate of flow of the stream.

5. An air sample contains 4.0 ppm(parts per million) of two pollutants. The concentration of one is four times the other. What are the concentrations.

6. a 5.0 piece of tubing weighs 1.7lb. What is the weight of a 27-ft piece of the same tubing.

7. A ship enters the red sea from the suez canal, moving south 17.4 mi/h. Two hours later, a second ship enters the Red Sea and the southern end, moving north at 21.8 mi/h. If the red sea is 1390 long. When will the ships pass?

8. Fifty pounds of cement sand mixture is 40% sand. How many pounds of sand must be added for the resulting mixture to be 60% sand?

9. a karat equals 1/24 part of gold in an alloy(for ex. a 9-karat gold is 9/24 gold). How many grams of 9-karat gold must be mixed with 18-karat gold to get 200g of 14-karat gold?

10. An alloy weighing 20lb is 30% copper. How many pounds of another alloy, which is 80% copper must be added for the final alloy to be 60% copper?