Help?​

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

What dimensions can créate more than one triangle ?

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?