I’ve got a calendar with usually fairly simple logic or math puzzles, but was unable to solve this. You are allowed to use multiplication, sum, minus and division to calculate the next number.
The answer was 58, but there was no explaining formula, does anyone have a clue?
Update: an example of another sequence that was much easier to solve is this:
9 - 17 - 14 - 22 - 19 - ?
Where the solution was simply alternating +8 and -3, so the answer here was