Why does the coefficient of performance of a refrigerator become infinity?

$A$ household refrigerator with a coefficient of performance $1.2$ removes heat from the refrigerated space at the rate of $60 \ kJ/min$. What would be the cost of running this fridge for one month $(30 \ days)$, assuming it is used for $4 \ hours$ each day and the cost of one electrical unit is $6 \ Rs.$?

The equation $\beta = \frac{Q_2}{Q_1 - Q_2}$ is true or false?

The coefficient of performance of a Carnot refrigerator working between temperatures $30 \, ^\circ\text{C}$ and $0 \, ^\circ\text{C}$ is:

If the coefficient of performance of a refrigerator is $5$ and it operates at a room temperature of $27\,^{\circ}C$,find the temperature inside the refrigerator.

If the sink and source temperatures of a refrigerator are $4^{\circ} C$ and $15^{\circ} C$ respectively,then the efficiency of the refrigerator is: