Pre-Algebra day 117

Sean sold 1/2 of his books, then bought 9 more. He now has 11. How many did he begin with ?

Which of the following sets represents the domain for the relation of: {(1,2),(3,4),(5,6),(7,8)}?

Bo is 2/3 of Dee's age & 2 years ago Dee was twice as old as Bo. How old will Bo be in 7 years?

simplify 2 -45/5+3-7(8)+63/(23-6(5)-2)

Choose all groups into which 2.215 fits: Natural, Real, Whole, Integer, Rational, Irrational.