We can replace the words for real values from above:
Alpha = (19262 CPM) – (14116 CPM) = 5146 CPM
Beta = (14116 CPM) – (1392 CPM) = 12724 CPM
Gamma = (1392 CPM) = 1392 CPM

The results sum back to the total, which helps us check our work:
Alpha + Beta + Gamma = 5146 CPM + 12724 CPM + 1392 CPM = 19262 CPM
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Here’s that bit about the copper lol I added it for fun, but it is correct.
Sheilding HVL of Copper: 10.2 mm
Thickness of Sample: ~4mm
Most Common Energy of Gamma: 214Bi 609.31 keV at 44.8%
e^-log(2)4mm/10.2mm = 0.76199, where d/dx e^-((ln(2)/10.2mm)*x) = (4^((-2+x)/x) log(2))/x^2