so, the outcomes are as follows:
You get $6 with probability 0.2
You get $0 with probability 0.8
Expected payoff = 0.2*6 + 0.8*0 = 1.2
So on average, you are getting $1.2 back for every $1 you put in, and you should take this bet.
I assume you are treating this as a statistics problem rather than an economics problem. If you are studying this in the context of an economics course the answer depends on how risk averse you are.