The ratio of the number of hippos to the number of crocodiles at a watering hole is 4:3. Draw a double number line diagram that would show the number of crocodiles if there were 20 hippos. I really dont know how to draw a double number line diagram

Atourist boat is used for sightseeing in a nearby river. the boat travels 2.4 miles downstream and in the same amount of time, it travels 1.8 miles upstream. if the boat travels at an average speed of 21 miles per hour in the still water, find the current of the river.