A block of mass 10kg is kept on a rough inclined plane as shown in...

Block will be at rest

$mgsin \theta + 3N = P + f$

$10 \times 10 \times \dfrac{1}{\sqrt{2}} + 3 = P + \mu mgcos \theta$

( $∵$ To get $P$ minimum friction must be minimum)

{P}_\min = 50\sqrt{2} + 3 - 0.6 \times 10 \times 10 \times \dfrac{1}{\sqrt{2}}

$= 20\sqrt{2} + 3 = 32N$