1. Charlie had the map open. "We've come just half way, exactly twenty miles," he said. "It must be the scenery, but you've been driving so slowly." "Yes, I know," Ben told him. "We averaged only 30 miles per hour so far, and I'd like to make that figure 60 for the complete run. Is there a speed I can average for the next twenty miles to hit my goal?" You find the answer!

160 miles per hour

120 miles per hour

No - the speed would have to be infinite