see dost solving pully prob is very easy what u need is a bit of practice

as far as the ques no 30 goes the block kept on the surface is acted upon by the tension there writing eq for it

T=Ma

T=a(mass=1)

writing eq for the second block

Mg-T=ma

g=2T

ttherefore T=5n

just practice dude success will surely come!!

do rate if satisfied

me wring sol 2 ur 2n prob jst wait!