Question

You plan a trip on which you want to average a speed of 90 km/hr. The first half of the trips distance was spent going 50 km/hr, so what must the average speed be in the second half of trip be in order to meet your goal?

Answer 1

\[90=\frac{50+r_{2nd}}{2}\]where \(r_{2nd}\) is the MUST average speed in the 2nd half of trip to meet the goal of 90 kph...