please help and explain why Geoff is incorrect

Answer:
Craig
Step-by-step explanation:
We can see this with an equation :)
Craig equation: 3x
Geoff: 1/2x
If we put in values for x, we can see who is going faster :)
Craig: 3(2)
6
Geoff: 1/2(2)
1
Have an amazing day!!
Please rate and mark brainliest!!