What is the name for the area between two concentric circles?

You invested $5000 between two accounts paying 4% and 9% annual interest, respectively. if the total interest earned for theyear was $350, how much was invested at each rate? $was invested at 4% andwas invested at 9%.

The taxi fare in gotham city is $2.40 for the first 1 2 12 mile and additional mileage charged at the rate $0.20 for each additional 0.1 mile. you plan to give the driver a $2 tip. how many miles can you ride for $10?

Louis wants to give \$15 to kids who need school supplies. he also wants to buy a pair of shoes for \$39. how much money will he have to save for both?