physics question

[madah123]

I have this right or wrong question in physics that i know the answer to but not the way to solve it can you help me with it?:

2 identical springs were put Vertically. if one was pulled 5cm (spring1) and the other was pulled 10cm(spring2) and were left to move a simple harmonic motion would the periodic time for (spring2)be double the periodic time for (spring1).

The answer is wrong i think but i have to mathematically prove it so my teacher don't think i am doing it randomly
i think its wrong because according to the law for the periodic time
T=2pie x sqrt of m /sqrt of k
and k =f/x and since x is in the root it even if we double it we wont get double T or something like that?

[DarkBandit]

Awww your doing te same practical investigation as i did. Lemme try find it