Correct Option (2)
Let the total distance of the race be n kilometres.
The problem states that the runner completed 12 km, which constitutes 80% of the total race distance.
This can be mathematically represented as:
0.8n = 12
To determine the total distance n, we solve the equation:
n = 12 / 0.8
n = 15 km
Therefore, the total distance the runner was supposed to run in this event was 15 kilometres.
Incorrect Options:
The other options are incorrect as they do not align with the given condition that 12 km represents 80% of the total race distance.
- If the total distance were 14 km (Option 1), then 12 km would represent approximately 85.7% of the race (12/14 * 100).
- If the total distance were 16 km (Option 3), then 12 km would represent 75% of the race (12/16 * 100).
- If the total distance were 16.5 km (Option 4), then 12 km would represent approximately 72.7% of the race (12/16.5 * 100).
These percentages do not match the specified 80% completion rate.