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### Section 2.3 : Applications of Linear Equations

1. A widget is being sold in a store for $135.40 and has been marked up 7%. How much did the store pay for the widget? Solution 2. A store is having a 30% off sale and one item is now being sold for$9.95. What was the original price of the item? Solution
3. Two planes start out 2800 km apart and move towards each other meeting after 3.5 hours. One plane flies at 75 km/hour slower than the other plane. What was the speed of each plane? Solution
4. Mike starts out 35 feet in front of Kim and they both start moving towards the right at the same time. Mike moves at 2 ft/sec while Kim moves at 3.4 ft/sec. How long will it take for Kim to catch up with Mike? Solution
5. A pump can empty a pool in 7 hours and a different pump can empty the same pool in 12 hours. How long does it take for both pumps working together to empty the pool? Solution
6. John can paint a house in 28 hours. John and Dave can paint the house in 17 hours working together. How long would it take Dave to paint the house by himself? Solution
7. How much of a 20% acid solution should we add to 20 gallons of a 42% acid solution to get a 35% acid solution? Solution
8. We need 100 liters of a 25% saline solution and we only have a 14% solution and a 60% solution. How much of each should we mix together to get the 100 liters of the 25% solution? Solution
9. We want to fence in a field whose length is twice the width and we have 80 feet of fencing material. If we use all the fencing material what would the dimensions of the field be? Solution