Step-by-step explanation:
It is given that,
Work done, W = 240 J
Heat removed, Q = 610 J
(a) The refrigerator's coefficient of performance is given by :
![COF=(Q)/(W)](https://img.qammunity.org/2020/formulas/physics/college/k81a8c47asphuxept8mrhjtfw1z8m4m89u.png)
![COF=(610)/(240)](https://img.qammunity.org/2020/formulas/physics/college/qutuiijwd0zi2224itiy1l9ske3cnqs2zu.png)
COF = 2.54
(b) Let Q' is the heat per cycle is exhausted to the kitchen. It is given by :
Q' = Q + W
Q' = 610 + 240
Q' = 850 J
Hence, this is the required solution.