Answer: 0.26
Step-by-step explanation:
Binomial probability formula :-
, where P(x) is the probability of getting success in x trials , n is total number of trials and p is the probability of getting success in each trial.
Given : The probability of winning = 
Let X be the random variable that represents the number of sodas.
Since he is guaranteed that he will win one soda .
If Cody buys 6 sodas, then the probability that he will win at least one more soda will be :

Hence, the true probability he will win at least one more soda =0.26