(9.5•10^5)-(2.3•10^4)

Mary used 1/7 of a spool of ribbon to complete 4 projects. she used the same amount of ribbon on each project. how much ribbon did she use on each project?

Charlie tosses five coins.what is the probability that all five coins will land tails up.

The bolo cavern outside of vandalia is 421 ft below sea level. a little more than75 miles away. mt owens is 7295 feet above sea level. what is the difference in elevation between the bolo cavern and mt owens?