An aircraft travels 2000 km from winnipeg to montreal in 3.2 hours and returns in 4 hours. if the wind speed is constant, find the wind speed and the speed of the aircraft in still air.

Celeste wants to have her hair cut and permed and also go to lunch. she knows she will need $50. the perm cost twice as much as her haircut and she needs $5 for lunch. how much does the perm cost?

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?