Question

How do you evaluate 10c3?

Answer 1

`10C3 = 120`

Explanation:

`color(white)("x")_(10)C_3`

`color(white)("XXXX")=(10!)/((10-3)! * (3!))`

`color(white)("XXXX")=(10 xx 9 xx 8 xx cancel(7 xx 6 xx ... xx1))/(cancel(7 xx 6 xx ... xx 1) * (3 xx 2 xx1))`

`color(white)("XXXX")=(10 xx cancel(9)^3 xx cancel(8)^4)/(cancel(3) xx cancel(2) xx1)`

`color(white)("XXXX")=120`