Which fraction is equivalent to 6/12

What is the least common factor of 6 and 8

Quadrilateral abcd in the figure below represents a scaled-down model of a walkway around a historic site. quadrilateral efgh represents the actual walkway. abcd is similar to efgh. what is the total length, in feet of the actual walkway?

The? half-life of a radioactive substance is 20 years. if you start with some amount of this? substance, what fraction will remain in 120 ? years