The ratio of people who walk home from school to people who ride the bus home is 2:7. The number of bus riders is how many times the number of walkers?
The number of bus riders is 3.5 TIMES the number of walkers. I divided 7 by 2, because they're asking for how many times are the Bus Riders larger than the walkers, and once that is done, you would get 3.5.