What are the masses of objects 1 and 3? Explain

Questions are about Forces and Newton’s Laws of Motion

1111 Figure P4.13 shows an acceleration-versus-force graph for three objects pulled by identical rubber bands. The mass of object 2 is 0.20 kg. What are the masses of objects 1 and 3? Explain your reasoning.
a (ml s2)
5
4
3
2
1
0
FIGURE P4.13
1 2 \ ../3 0 1 2 3 4 5 6
Force (number of rubber bands)