Compounding is regular addition of interest to the invested amount of money at agreed intervals of time over the investment duration. Compounding can be done at popular time intervals such as monthly, quarterly, half-yearly and annually.
Average speed is determined by applying the formula: (total distance travelled/total time taken). Average speed will be same as average of the two speeds if the two distances are travelled at same speeds. Otherwise, average speed over two different distances travelled at different speeds will be less than the average of the speed numbers.