Hi there,
In question #8, Greg says 4!/2! is 6, but isn’t it 12? ((4x3x2x1)/(2x1)) = 4x3 = 12
4! / 2! is indeed 12.
However, in the solution, Greg is computing 4C2, which is 4! / 2!2! = 6.
Basically, the binomial theorem is used for every case (one 4, two 4, three 4, four 4)
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