If an athlete runs at a speed of 12.9 km/hour, how long will it take the athlete to run a marathon (about 42.2 km) ? Express your answer in hours using the correct number of significant figures. Do not enter your answer using scientific notation.

Time = 3.27s

Explanation:

Time = Distance / Speed

Time = 42.2 / 12.9 = 3.2713

When you multiply the number of significant figures in the result is the same as the number with the least significant figures.

In this case 42.2 has 3 significant figures and 12.9 also has 3 significant figures, therefore the answer must have 3 significant figures too.

Time = 3.27 s