Assignment:
Translate the following problems into a pair of linear equations in two variables. Solve the equations using either elimination or substitution. State your answer for the specified variable and please show your work.
Q1. A plane flies 400 miles with the wind and 300 miles against the wind in the same length of time. If the speed of the wind is 22 mph, what is the speed of the plane in still air?
Q2. Jill is 11 kilometers away from Joe. Both begin to walk toward each other at the same time. Jill walks at 2.5 km/h. They meet in 2 hours. How fast is Joe walking?
Q3. How many liters of a 40%-alcohol solution must be mixed with 10 liters of a solution that is 80% alcohol to get a solution that is 60% alcohol?
Provide complete and step by step solution for the question and show calculations and use formulas.