If the Taylor's tool life exponent n is 0.2, and the tool changing time is 1.5 min, then the tool life (in min) for maximum production rate is::

The Taylor's tool life equation is given by:

VT^n = C

where: V = cutting speed T = tool life n = tool life exponent C = constant

The question provides the tool life exponent (n) as 0.2, but does not provide the cutting speed (V) or the constant (C). Therefore, we cannot directly calculate the tool life (T) from the given information.

However, the question asks for the tool life for maximum production rate. The production rate is typically maximized when the tool life is minimized (since a shorter tool life means that the tool can be replaced more frequently, allowing for faster cutting speeds).

Given that the tool changing time is 1.5 min, we can infer that the tool life for maximum production rate would be slightly more than this (to account for the time it takes to actually perform the cutting). However, without more specific information, we cannot provide a more precise answer.