The momentum of ball is given by:
[tex]\Delta Q=mv \\ \Delta Q=6*10^{-2}*60 \\ \Delta Q=3.6kg*m/s[/tex]
Since both have the same momentum, we have:
[tex]\Delta Q=MV \\ 3.6=10^{-2}V \\ \boxed {V=360m/s}[/tex]
Number 3
If you notice any mistake in my english, please let me know, because i am not native.