There are 40 tables in a library, with 30% of them seating 4 people. the tables remaining only seat 2 people. how many seats are there in the library?

Two planes leave an airport at the same time, one flying east, the other flying west. the eastbound plane travels 20 mph slower. they are 1600 mi apart after 2 hr. find the speed of each plane.

How many $20 bills do you need to have to make $280

Acircle has a radius of 5/6 units and is centered at (3.6, 7.8) write the equation of this circle