help!!

let us analyse this force-method...
impulse provided by particle = change in momentum of particle = 0.25(200-100) = 25 kgm/s = ∫Fdt

Let impulse by tension be ∫Tdt
Let the velocity of A after bullet leaves be V .. vel of B after bullet leaves is also V by constraint.

For A,
∫Fdt - ∫Tdt = 1*V ... (I)

For B, ∫Tdt = 2*V ... (II)

adding.
∫Fdt = 3V ==> V=25/3 m/s
Impulse by string = ∫Tdt = 2V = 50/3 kgm/s

after bullet comes out the acceleration of the system is 2g/3 downwards.. i.e. 20/3 m/s²

So, max displacement of A towards left is given by
0 - (25/3)²= -2*20/3*X
==> X = 625/9*3/40 = 5.2 m ...

So A=r
B=s/10
C=p
D=q

calculation mistakes possible