Answer
5 to 2
Work Step by Step
Simplify by eliminating common factors from each side of the ratio.
$30\ to\ 12$ is the same as:
$(5\times3\times2)\ to\ (3\times2\times2)$
Eliminate common factors.
$(5\times/\!\!\!3\times/\!\!\!2)\ to\ (/\!\!\!3\times/\!\!\!2\times2)$
Which leaves:
$5\ to\ 2$
