Solution:

From figure, DEF is the area of the gas’s total work done from D through E and F.

Area of ∆DEF = (1/2) x DE x EF

Where,

DF = Change in pressure = 600 N/m² – 300 N/m²= 300 N/ m²

FE = Change in volume = 5.0 m³ – 2.0 m³= 3.0 m³

Area of ∆DEF = (1/ 2) x 300 x 3

On further evaluation, we get,

= 450 J

Hence, the total work done by the gas from D to E to F is 450 J