[tex]\bold{ANSWER:}[/tex]
[tex]\small\textsf{1.) 56}[/tex]
[tex]\small\textsf{2.) r = 3}[/tex]
[tex]\bold{SOLUTION:}[/tex]
1.) Given: C(8,3)
To find: value
C(8,3) = 8!/3!(8 - 3)!
=(8×7×6)/6 = 56
2.) C(10,r) = 10!/r!(10 - r)! = 120
[tex]\small\textsf{take r = 3 into it}[/tex]
C(10,3) = 10×9×8/3×2 = 120
So, r = 3
