Time period of combination of massive springs in parallel

[Vashist Settipalli]

Let us say there are two springs each of mass m and each having a spring constant k.
If the two springs are connected in parallel to a mass M and are made to oscillate,
what will be the time period of oscillations??

 

[BvU]

If you had a choice, what would you say yourself ?
And: do you know the time period for a single spring with a mass M (assume an ideal spring) ?

 

[pixel]

Hint: when springs are connected in series or in parallel, there is an equivalent spring constant for the combination:
https://en.wikipedia.org/wiki/Series_and_parallel_springs