The answers are 30, 40, and 50.
EXPLANATION
You basically need algebra to solve this. Following the ratio, the equation will be like this:
3x+4x+5x=120
Now solve for x first.
12x=120
x=10
Then, substitute it to the values relayed by the ratio.
3x=3(10)=30
4x=4(10)=40
5x=5(10)=50
