7) A weather balloon is rising vertically. After r hours, its distance above the ground, measured in kilometres, is given by the formula s(t) = 8t - 12. a. Determine the average velocity of the weather balloon from t = 2 h to t = 5 h. b. Determine its velocity at t = 3 h. L(C-3 marks) 8) A few days after their intense conversation about limits, Jenny and Karlo went on a date. . While they were enjoying their meal, Jenny told Karlo that the expression f(x)-(5) is the x-5 slope of the tangent line to f(x) at the point where x = 5. Is Jenny's claim correct? Explain. (C-3 marks)