averages

What is the average (arithmetic mean) of x,y and z? 1) 3x-2y+7z = 23 2) 4x-3y+5z = 5 and -x+6y-2z = 58

Tracey ran to the top of a steep hill at an average pace of 6 miles per hour. She took the exact same trail back down. To her relief, the descent was much faster; her average speed rose to 14 miles per hour. If the entire run took Tracey exactly one hour to complete and she did not make any...

The doc file contains some sums on averages .