This is a question from a competitive test. I am not sure how to reason this out. By the length of the string, S should have the maximum amplitude. But this would be the case only when the pendulum P hits pendulum S at the point where the mass lies (the bob itself at point S). However, P is quite short for that.
Now if it hits pendulum R, then it would hit the approximately at the bob, resulting in good application of force.
However, since pendulum S is longer, it would move easily.
So the NARROWED QUESTION:
If a bob hits another bob and if a bob hits another string with a bob attached to it, the first bob and string at the same height, what effect would it have on the energies associated with the bob which gets directly hit, and on the bob which gets displaced as a result of the rope.