1. The problem states that Niall has cycled 4.1 km out of a total distance of 10 km. 2. We need to find the fraction of the total distance that Niall has cycled. 3. The fraction is given by the distance cycled divided by the total distance: $$\frac{4.1}{10}$$. 4. To simplify this fraction, multiply numerator and denominator by 10 to remove the decimal: $$\frac{4.1 \times 10}{10 \times 10} = \frac{41}{100}$$. 5. Check if this fraction can be simplified further by finding the greatest common divisor (GCD) of 41 and 100. 6. Since 41 is a prime number and does not divide 100, the fraction $$\frac{41}{100}$$ is already in its simplest form. Therefore, Niall has cycled $$\frac{41}{100}$$ of the total distance.