Answer:
Final length= 746.175 mm
Step-by-step explanation:
Given that Length of aluminium at 223 C is 750 mm.As we know that when temperature of material increases or decreases then dimensions of material also increases or decreases respectively with temperature.
Here temperature of aluminium decreases so the final length of aluminium decreases .
As we know that

Now by putting the values

ΔL=3.82 mm
So final length =750-3.82 mm
Final length= 746.175 mm