1). A store owner want to develop a new snack mix by mixing chocolate and trail mix. How many pounds of chocolate costing $8.70 per pound should be mixed with trail mix costing $4.50 per pound to create a 31 mixture worth $5.85. (round to the nearest pound)
The owner needs to mix x pounds of chocolate and x pounds of trail mix.

2). A store owner want to develop a new snack mix by mixing chocolate and trail mix. How many pounds of chocolate costing $21.40 per pound should be mixed with 18 pound of trail mix costing $3.10 per pound to create a mixture worth $10.04. (round to the nearest pound)

3). Nuri needs to mix a 20% acid solution with a 60% acid solution to create 200 milliliters of a 56% solution. How many milliliters of each solution must Nuri use?

4).You need 300 mL of a 90% alcohol solution. On hand, you have 45% alcohol mixture. You also have 95% alcohol mixture. How much of each mixture will you need to add to obtain the desired solution?

5). You need a 75% alcohol solution. On hand, you have a 90 mL of a 25% alcohol mixture. You also have 90% alcohol mixture. How much of the 90% mixture will you need to add to obtain the desired solution?

6). You need a 90% alcohol solution. On hand, you have a 20 mL of a 65% alcohol mixture. You also have 95% alcohol mixture. How much of the 95% mixture will you need to add to obtain the desired solution?

7). If you wanted to mix pure methane with water and end up with 130 gallons of 10% methane, how many gallons of each should you use?

8). A boat travels upstream for 96 miles in 4 hours and returns in 3 hours traveling downstream in a local stream of water. What is the rate of the boat in still water and the rate of the current?

9). A man flies a small airplane from Fargo to Bismarck, North Dakota --- a distance of 180 miles. Because he is flying into a head wind, the trip takes him 2 hours. On the way back, the wind is still blowing at the same speed, so the return trip takes only 1 hour 12 minutes. What is his speed in still air, and how fast is the wind blowing?