Answer:
100% cold working performed on this steel
Explanation:
Using the constant volume assumption:
L₀W₀t₀ (initial) = Lₐ Wₐ tₐ (final)
thus 300 cm long X 80 cm wide X 8 cm thick = Lₐ x 80 cm wide X 5 cm thick
Lₐ = 300 cm long X 80 cm wide X 8 cm thick/80 cm wide X 5 cm thick
=480 cm
% cold working performed on this steel = Lₐ Wₐ tₐ (final) / L₀W₀t₀ (initial) 8 100
= 480 x 80 x 5/ 300 x 80 x 8 *100 = 100%