The force of friction on the block in case 1 will be = uN
The normal on the block will be reduced due to the vertical component of the FA .
which is equal to - FAsin30 = FA/2.
The net normal force on the block = (mg-FA/2)
Therefore, the frictional force on the block =
This frictional force will balance the horizontal component of the force that is - FAcos30 = FA3*(1/2)/2
umg-uFA/2 = FA3*(1/2)/2
FA = umg/3*(1/2)/2+u/2
Similarly, we can find the value of FB using the angle as 60. And can find FA/FB by putting the value of coefficient o friction (u).