Question

A key code must contain 4 numerals. There are 10 numerals available. Using

Answer 1

Answer:

B, 210

Step-by-step explanation:

$\dbinom{10}{4} = \dfrac{10!}{6! \cdot 4!} = \dfrac{10 \cdot 9 \cdot 8 \cdot 7}{4 \cdot 3 \cdot 2 \cdot 1} = 5 \cdot 3 \cdot 7 \cdot 2 = 210$