Question

please answer fast as soon as possible

Answer 1

make fbd of all three blocks as well as system
then you will get following equations
F-T1=m×a
T1-T2=3ma
T2=5ma
F=9a
since all will have the same acceleration
now substitute the value of T1 and solve the 4 equations
as there are 4 equations and 4 variables you can easily find out the answer
you will get the following results
a=3m/sec square
T2=15N
F=27N