Question

What is the underlying complexity decimal numbers were used to represent

Answer 1

The underlying complexity decimal numbers were used to represent are bits, the decimal numbers were helpful in designing a system to represent text in bits because it is easier to read and it separates different texts.

Step-by-step explanation:

Answer 2

If we are talking about computer science:

The decimal numbers are the numbers that we use every-day (0, 1, 2, 3, 4, 5, 6, 7, 8, 9)

The use of these "symbols" facilitates a lot of things because the decimal numbers are easier to read and use than the binary system, so the "underlying complexity decimal numbers were used to represent" are the bits.