The scale of a dollhouse is 1:12 . If it is modeled after an actual house that is 40 feet tall, how tall is the dollhouse? A: 4 1/2 feet tall
B: 4 feet tall
C: 2 3/4 feet tall
D: 3 1/3 feet tall

Asocial networking site currently has 400,000 active members, and that figure is predicted to increase by 32% each year. the following expression represents the number of active members on the site after t years.

Acollection of coins has value of 64 cents. there are two more nickels than dimes and three times as many pennies as dimes in this collection. how many of each kind of coin are in the collection?

Bob is putting books on a shelf and takes a break after filling 18 1/2 inches on the book shelf. the book shelf is now 2/3 full. how long is the entire bookshelf?