Number Systems

Step 1: Understanding the 9's complement.
To compute the 9's complement of a decimal number, subtract each digit from 9.

Step 2: Computing the 9's complement of 782.54.
For the integer part , subtract each digit from 9: - - -

So, the 9's complement of 782 is 217.

For the fractional part , subtract each digit from 9: - -

Thus, the 9's complement of 782.54 is 216.45.

Therefore, the correct answer is (1) 216.54.