> For the complete documentation index, see [llms.txt](https://metis-montessori-lyceum.gitbook.io/sql-0/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://metis-montessori-lyceum.gitbook.io/sql-0/4-grouperen/opdrachten.md).

# Opdrachten

#### Opdracht 4.1

Maak een lijstje met aantallen employees per plaats.

#### Opdracht 4.2

Hoeveel tracks zijn er per Genre aanwezig?

#### Opdracht 4.3

Bij welke Genre zijn er meer dan 10 aanwezig?

#### Opdracht 4.4

Geef de gemiddelde lengte van een track per Genre, maar dan alleen als de lenge hoger is dan 250000.

#### Opdracht 4.5

Maak een overzicht van het aantal tracks per GenreID en de totale lengte (in ms) per GenreID. 

Voorbeeld:

`1|1297|368231326` \
`2|130|37928199` \
`3|374|115846292` \
`4|332|77805478`\
`5|12|1615722` 


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