In a special code language, colour names are changed as follows: white is called black, black is called red, red is called yellow, yellow is called green, green is called blue, blue is called violet and violet is called orange. Under this code, what would be the stated colour of human blood?

Introduction / Context:
This problem is a typical example of a coding or substitution question often seen in analytical reasoning. Real world labels are reassigned in a systematic way, and you must mentally translate from the actual property to the new coded label. Here colour names are remapped, and you must identify the coded name that corresponds to the real colour of human blood.

Given Data / Assumptions:

• Real world fact: healthy human blood is red in colour.
• The coding scheme is:
  • white is called black
  • black is called red
  • red is called yellow
  • yellow is called green
  • green is called blue
  • blue is called violet
  • violet is called orange
• We must find the word used in the code language for the real colour red.

Concept / Approach:
The key idea is to separate the actual colour from the new name used for it. We first determine the actual colour of human blood, which is red. Then we look in the given mapping for the rule that tells us what the code language calls red. We must not be distracted by what red is called in normal language, but only use the information from the mapping table provided.

Step-by-Step Solution:
Step 1: Recall that human blood is naturally red in colour. Step 2: From the code mapping, identify the statement that involves red: 'red is called yellow'. Step 3: This means that whenever something is actually red, in the code language people will say 'yellow'. Step 4: Since blood is actually red, in the code language its colour will be stated as yellow. Step 5: Therefore, among the options, 'Yellow' is the correct answer.

Verification / Alternative check:
As a quick check, you can write a small mapping table: actual red → stated yellow, actual black → stated red, actual white → stated black, and so on. For blood you start on the actual side with red and then move to the code side, which is yellow. No other mapping step connects directly to the actual colour of blood, so there is no ambiguity.

Why Other Options Are Wrong:

• Green: This is the coded name for actual yellow, not for red.
• Black: This is the coded name for actual white, not relevant for blood.
• Red: This is the coded name for actual black, so it does not represent actual red in this code.
• Blue: This is the coded name for actual green, again unrelated to the actual colour of blood.

Common Pitfalls:
Many learners forget to separate the actual property from the new label and choose red simply because they know blood is red. Others read the mapping backward and think that because something is called yellow it must be red, confusing the direction of the mapping. Drawing a simple two column list (actual colour versus coded name) and following it carefully prevents such errors.

Final Answer:
Under the given code language, the colour of human blood would be stated as Yellow.