Classity each of the following as element, compound, or mixture

Atrain travels 74 kilometers in 3 hours, and then 81 kilometers in 5 hours. what is its average speed?

If 1.8 l of water is added to 2.5l of a 7.0 m koh solution, what is the molarity of the new solution

Acm ruler with main graduations from 1 to 10 from left to right there are 10 secondary graduations between each of the main graduations there is a line that begins. at the left end of the ruler 10 secondary graduations to the left of the “1 main graduation the right end of the line ends on the eighth secondary graduation to the right of 3 how long is the line