Two blocks A and B of masses m _ A = 1kg and m _ B = 3kg are kept...

Two blocks $A$ and $B$ of masses ${m}_{A} = 1kg$ and ${m}_{B} = 3kg$ are kept on the table as shown in figure. The coefficients of friction between $A$ and $B$ is $0.2$ and between $B$ and the surface of the table is also $0.2 .$ The maximum force $F$ that can be applied on $B$ horizontally, so that the block $A$ does not slide over the block $B$ is : [Take $g = 10m / {s}^{2}$ ]