How many millimeters are in 5 inches?

To convert inches to millimeters, it is essential to understand the conversion factor between these two units. One inch is equivalent to 25.4 millimeters. Therefore, to find out how many millimeters are in 5 inches, you would multiply 5 by 25.4.

The calculation is as follows:

5 inches × 25.4 mm/inch = 127 mm.

This shows that there are 127 millimeters in 5 inches. This makes the choice of 127 mm the accurate and correct answer.

The other options, while they might seem plausible, do not reflect the correct multiplication of the conversion factor with 5 inches. 135 mm, 150 mm, and 120 mm do not account for the exact measurement derived from the conversion, leading to their inaccuracy.