Final answer:
To determine the distance run by a marathon runner after completing 35% of a 40-kilometer race, multiply the total kilometers (40) by 0.35. The runner has therefore completed 14 kilometers of the marathon.
Step-by-step explanation:
To calculate how many kilometers a marathon runner has raced when they have completed 35% of the race, we use the percentage of the race completed to determine the distance run. As mentioned, a marathon is usually 42.188 kilometers long; however, in the question, it is stated the marathon is exactly 40 kilometers. To find out how far the runner has gone after completing 35% of the marathon, we multiply 40 kilometers by 35% (or 0.35 in decimal form).
Here is the calculation:
Distance run = Total distance of the marathon × Percentage of the marathon completed
Distance run = 40 km × 35%
Distance run = 40 km × 0.35
Distance run = 14 kilometers
If a marathon runner has raced 35% of a full 40-kilometer marathon, they have run 14 kilometers.