A level maths mechanics vectors question

Can anyone explain c to me? I really don't get this topic

Hmm... Let's start with two questions:

(i) What does it mean, mathematically, to say "a particle is traveling in a direction"? Can you relate this to a vector of some quantity?
(ii) What property does "a vector parallel to the i direction" have? If you aren't sure, try drawing a bunch of vectors parallel to the i direction, write down their vector representations (in terms of i and j), see if you spot a pattern.

I know if it's moving in a direction, the velocity is added to the distance? And if it's travelling in the i direction its j component is 0. I did think to just add 5i to the origin so the answer would be 5i but that seems wrong and a bit too easy for a 6 marker.
I think I'm just missing an element cause suvat has to come in somewhere . Do I use s = ut +at^2? I'm unsure what values to put in though

Warning: you never add two quantities with different units!
The answer to part (i) of my motivation is simpler than you think. Think a bit more naively (often a good thing, btw) before checking the answer in spoilers.

Now, combine with the correct observation you've made that the j component is zero should give you the answer.

ah ok I think I get it. So if I find the time when the j component is 0 by using the velocity vector, then I can find the position vector through suvat right? Thanks for your help! I'll try it out