Question

For an office job I need to pick 3 candidates put of a pool of 5. How many choices do I have?

Answer 1

`C_5^3= (5!)/(3!(5-3)!)= (1*2*3*4*5)/(1*2*3*2!)= \\\\ =(4*5)/(1*2)= 2*5 \to\boxed{10-choices}`