In an interchangeable assembly, shafts of size 25.000 -0.010⁺⁰∙⁰⁴⁰ mm mate with holes of size 25.000 -0.020⁺⁰∙⁰³⁰, the maximum interference (in microns) in the assembly is

Answer: Option E

Understanding Interchangeable Assembly:
Imagine you're building something with lots of parts, like a machine. An interchangeable assembly means all the parts are made to precise sizes so they fit together perfectly, no matter which part you pick.

Shafts and Holes:
In this question, we have shafts (like rods) and holes. The sizes are given with tolerances (the allowed variation).

Understanding the Size Notation:
For example, "25.000 -0.010⁺⁰∙⁰⁴⁰ mm" for the shaft means:
* 25.000 mm is the basic size.
* -0.010 mm is the lower limit (the shaft can be 0.010 mm smaller than 25.000 mm).
* +0.040 mm is the upper limit (the shaft can be 0.040 mm larger than 25.000 mm).

Similarly, "25.000 -0.020⁺⁰∙⁰³⁰ mm" for the hole means:
* 25.000 mm is the basic size.
* -0.020 mm is the lower limit.
* +0.030 mm is the upper limit.

Finding Maximum Interference:
Interference happens when the shaft is bigger than the hole. Maximum interference means finding the biggest possible difference between the largest shaft and the smallest hole.
* Largest Shaft: 25.000 + 0.040 = 25.040 mm
* Smallest Hole: 25.000 - 0.020 = 24.980 mm
* Maximum Interference: 25.040 - 24.980 = 0.060 mm

Converting to Microns:
1 mm = 1000 microns
Therefore, 0.060 mm = 0.060 * 1000 = 60 microns

Therefore, the correct answer is E: 60