Answer
375 J. Heat is transferred to the system.
Work Step by Step
Given that, ∆E= 300 J
Also, w= -75 J ( The sign is taken as negative as the work is done by the system)
Using the relation ∆E = q+w,
We get, q = ∆E-w = 300 J -(-75 J) = 375 J.
Positive sign of q indicates that the heat is transferred to the system.