Divya spends all of her free time playing with her building blocks. She owns building block sets with $3$ pieces, $5$ pieces, and $10$ pieces.
Divya knows she owns $5$ sets with $5$ pieces and $2$ sets with $10$ pieces. She also knows that she averages $5$ pieces per set. This information is summarized in the table below.
**Fill in the missing blank with how many sets with $3$ pieces Divya owns.**
Pieces in a set| Sets
:-: | :-:
$3$ | [[☃ input-number 1]]
$5$ | $5$
$10$ | $2$