See there is no pink
So probability of selecting a pink is 0 .
The probability of orange is 20% or 0.2
The probability of purple is 30% or 0.3
As there is no color mentioned for rest part at max probability of pink is 0.5 .
- But by now it's 0 as it's not mentioned
120 - 4 - 6 = ( that is the process, you ca find the answer)
For this case we have to write the equation of the position of each one.
We have then:
For the robber:

For the marshall
:


By the time the marshall reaches the robber we have:

From here, we clear the time.
We have then:




Answer:
it takes the marshall to catch up to the robber about 2.7 hours.
Your answer would be X=8 and Y=11.