Apilot took off and brought her airplane to an elevation of 15,000 feet. over the next 2 hours, the pilot change the elevation of her plane several times, as listed in feet: -2,500+3,000-1,000+2,500-3,000what is the elevation of the pilot's plane after the 2 hours?

Astudent must have an average on five test that is greater than it equal to 80% but less than 90% to receive a final grade of b. devon's greades on the first four test were 78% 62% 91% and 80% what range if grades on the fifth test would give him a b in the course? ( assuming the highest grade is 100%)