Question

How many combinations exist of the letters W, X, Y, Z, taking two at a time? 04 06 012

Answer 1

Step-by-step explanation:

C(4,2)

Use combinations formula,

c(n,r)=n!/r!(n-r)!

c(n,r)=4!/2!(2!)

$c = \frac{4 \times 3 \times 2 \times 1 }{2 \times 1 \times 2 \times 1}$

$c = 3 \times 2 \times 1$

$c = 6$