The probability that Henk goes swimming on any day is 0.2. On a day when he goes swimming, the probability that Henk has burgers for supper is 0.75. On a day when he does not go swimming, the probability that he has burgers for supper is x. This information is shown on the following tree diagram.

The probability that Henk has burgers for supper on any day is 0.5.

(i) Find x.

(ii) Given that Henk has burgers for supper, find the probability that he went swimming that day.