net count due to the source

[rawia]

Qustion ,try to solve ??.
*Hi *
*I am looking to solve this qustion ,please id any one can help me i will apperiate that *

*A source counted for 1 minutre and gives 561 counts , the source is removed and 1 minute background 410 counts ,what is net count due to the source along and its associated standted deviation ??*

*as soon as possible*

Dear alanamede this your quastion ,it maybe removed or didn’t load right so I put it in new title
and I’ll answer it

N (net count due to the source)=counts appered on counter (with source)-background counts
=561-410=151counts
and standared deviation=root(N)=12.2882