Explain why hexadecimal is used by computer scientists

Hexadecimal numerals are widely used by computer system designers and programmers. As each hexadecimal digit represents four binary digits (bits), it allows a more human-friendly representation of binary-coded values. Onehexadecimal digit represents a nibble (4 bits), which is half of an octet or byte (8 bits).

           
  
            " The main reason why we use hexadecimal numbers is because it is much easier to express binary number representations in hex than it is in any other base number system." - http://digiassn.blogspot.com/2006/02/why-do-we-use-hexadecimal.html

The answer is "a"radius = 12.7 unitsdiameter = radius × 212.7 units × 2 = 25.4 units