There are 15 people at a block club meting. how many different committees of 2 people can be formed
1. 15
2. 30
3. 105
4. 210

If 10 men take 18 days to mow 60 acres of grass, how long will 15 men take to mow 80 acres?

Maurice has 54 fewer comic books than rebecca.they have 130 comic books together .how many comic books are in maurices collection ? how many comic books are in rebeccas collection

This is a map of the mars exploration rover opportunity predicted landing site on mars. the scale is 1cm : 9.4km. what are the approximate measures of the actual length and width of the ellipse? i mostly need to know how to set it up : )