Need help with counting cells

[JLandrum]

Newbie
Can someone plz help this lost soul. Please see attached. What I need or trying to do is get information from b11,b50 and have a total in b5. the columns are filtered with column B having multiple data.
When column B is filtered with only BKS or SLC or MCP, B5 would count what is visible.
Another option if possible (preferred), B5 count any visible items in column B. Thanks for any help

[Jonmo1]

Try

=SUBTOTAL(103,$B$11:$B$51)

[JLandrum]

Awesome, thanks for the help

[Jonmo1]

You're welcome.