Please explain these math questions!

1) How many cm2 in 1m2?
2)How much are 7 pencils at 3 for $1.65
3) Is a hectare roughly equal to 2 tennis courts or 2 soccer fields?
4) Add all the odd numbers between 20 and 30. (I don't understand)
5) How many axes of symmetry has a rhombus?