In 2005, 8.1x10^10text messages were sent in the united states. in 2010, the number of annual text messages had risen to 1,863,000,000,000. about how many times as great was the number of text messages in 2010 then 2005?

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class

Atruck travels from a factory to a gas station in 4 minutes. it stops at the gas station for 3 minutes. the truck then returns to the factory in 3 minutes. which graph best represents the distance, y, in miles, of the truck from the factory for a certain amount of time, x, in minutes?

Which is the equation of an ellipse centered at the origin with endpoints of major and minor axes at : (0, -7), (0, 7), (-3, 0), (3, 0)?