Can the coefficient of performance of a refrigerator be increased by increasing the mass of the working substance?

An ideal refrigerator has a freezer at a temperature of $-13^{\circ} C$. The coefficient of performance of the refrigerator is $5$. The temperature of the air (to which heat is rejected) is:

Assertion $(A)$: $A$ room can be cooled by opening the door of a refrigerator in it.
Reason $(R)$: Heat always flows from a body at higher temperature to a body at lower temperature.

$A$ Carnot engine,having an efficiency of $\eta = 1/10$ as a heat engine,is used as a refrigerator. If the work done on the system is $10 \ J$,the amount of energy absorbed from the reservoir at a lower temperature is ....... $J$.

If the coefficient of performance of a refrigerator is $\beta$ and the heat absorbed from the refrigerated space is $Q$,then the work done on the system is:

Explain the working of refrigerators/heat pumps and their coefficient of performance.