Answer:
59.52 J.
Step-by-step explanation:
The Formula of Coefficient of performance is given as,
η = Q/W ........................ Equation 1
Where η = Coefficient of performance, Q = The heat from the interior, W = Work done by the refrigerator.
make W the subject of the equation
W = Q/η .................. Equation 2
Given: Q = 250 J, η = 4.2
Substitute into equation 2
W = 250/4.2
W = 59.52 J.
Hence the work done by the refrigerator = 59.52 J.