Preflop odds to play speculative hands such as K3s

[Poker Clif]

When talking about playing speculative hands, I often read about needed a certain number of callers/limpers to play hands such as K3s or 67s. However, I've don't recall anything specifically mathematical about such hands.

As an example, early in 180 player SNG I had K3 in the big blind. Blinds were 15/30. One caller, and it's to me with 75 in the pot.

One the one hand, there is only one limper to play a speculative hand. One the other hand, I'm getting 5:1 (75:15) to call.

Is this a call?