You are an engineer building a spaceship. If the length of the fuel tank is scaled up by 100 times, what is the length of the fuel tank on the actual spacecraft?

To determine the length of the fuel tank on the actual spacecraft after scaling it up by 100 times, it is crucial to understand what the scaling factor means. Scaling an object's dimension by a factor of 100 implies that the new length is 100 times the original length.

Assuming the original length of the fuel tank is 0.25 m (which equals 25 cm), scaling it up by 100 times would result in:

Original length: 0.25 m * 100 = 25 m.

This means that the length of the fuel tank on the actual spacecraft is 25 meters. Thus, option A, which states 25 m, accurately reflects the result of the 100-fold increase in length.

It’s important to recognize that other options present lengths that either do not conform to the mathematics of scaling or serve different units of measure, making them not applicable in this scenario. For example, 1000 cm converts to 10 m (not 25 m), 25 km is significantly larger than any practical fuel tank length, and 2500 mm converts to 2.5 m (also not 25 m). Therefore, 25 m is indeed the correct answer based on the scaling calculation.