Answer: [tex]14:3[/tex]
Step-by-step explanation:
You can use ratio to compare values.
By definition, ratios can be written in the following form:
[tex]a:b[/tex]
In this case, you know that the number of pieces of different rocks that Diana has in her collections, are:
[tex]granite=6\ pieces\\\\marble=3\ pieces\\\\sandstone=14\ pieces\\\\slate=1\ piece[/tex]
Since you must compare the number of pieces of sandstone and the number of pieces of marble in Dana's collection, you need to write the following ratio:
[tex]sandstone:marble\\\\14:3[/tex]