Finding scalars from vectors

(__Note:__ the **bold** letters are vectors.)

"Find the scalars, α and β and such that

(i) 3**i** + **j** is parallel to α**i** - 4**j**

(ii) 3**i** + β(**j** - **k**) is parallel to **i** - 4**j**+ 4**k**

(iii) 3**i** + γ(**j** + 3**k**) has the same length as 12**i** - 5**k**"

I first assumed that since the vectors are parallel, they would be equal to each other. So, as for (i), and assuming that **v** = 3**i** + **j**, I found |**v**| as assumed that would be the length and thought that finding the length of the other vector through solving it that way would be the right approach. However, I realised that it isn't.

I did have a peep at the answers although, that's all that was there so that was hardly any help. (If it is needed - (i)-12 (ii)-12 (iii) ±4). I tried looking over my course notes and even the appropriate section from my textbook but, I can't find anything that is similar to this question.