Step 1: Understanding the Colours of the Rainbow.
A rainbow consists of 7 distinct colours that appear due to the dispersion of light through water droplets, creating a spectrum. These colours are traditionally remembered with the acronym "ROYGBIV," representing:
- Red
- Orange
- Yellow
- Green
- Blue
- Indigo
- Violet
Step 2: Verifying the Options.
- Option (1): 7 is correct, as there are 7 colours in the rainbow.
- Option (2): 5 colours is incorrect.
- Option (3): 4 colours is incorrect.
- Option (4): 6 colours is incorrect.
Conclusion:
Therefore, the correct answer is (1) 7, as there are 7 colours in a rainbow.