Answer: The minimum diameter of the cylinder is 86.3975 millimeters
Solution:
dmin=d-t
Minimun diameter: dmin=?
Diameter: d=86.4 millimeters
Tolerance: t=0.0025 millimeters
Replacing the values:
dmin=86.4 millimetres-0.0025 millimetres
dmin=86.3975 millimetres