1.From a point on level ground 90 feet from the base of a building, the angle of elevation is 25.6^o. Apprroximate the height of the building to the nearest foot.

2.A chemist needs to mix an 18% acid solution with a 45% acid solution to obtain 12 liters if 36% acid solution. How many liters of each of the acid solution must be used?

3.You have 600 feet of fencing to enclose a rectangular plot that borders on a river, find the plot that will maximize the area. What is the largest area that can be enclosed?

4.With the current, a motorboat can travel 85 miles in 2 hours. Against the current, the same trip takes 3 hours. Find the average velocity of the boat in still water and the average velocity of the current.

5.A company that manufactures running shoes has a fixed cost of $300,000. Additionally, it costs $30 to produce each pair of shoes. They are sold at $80 per pair. How many pairs of shoes must be solve to break even?