Submitted result's score for Final Assessment Quiz (CMI5)

Hello E-Learning Heroes! I'm very new to Storyline 360, Currently I'm testing a super simple course with assessment quiz, I got an impression that the course is always sending its quiz result in 0%, 25%, 50%, 75%, 100% basis.  For example if there's 3 questions and each has 10 points, and a learner gave a only one correct answer(10 point), I expect the submitted result statement from LMS side would be 33.333%(scaled) or 10 point (raw) but the course actually sent a 50% of result score. The course in question is attached in this post.

Actual LRS statement:

"result": {
  "success": false,
  "duration": "PT23.6S",
  "score": {
  "scaled": 0.5,
  "raw": 50,
  "min": 0,
  "max": 100
}

What I Expected:

"result": {
  "success": false,
  "duration": "PT23.6S",
  "score": {
  "scaled": 0.33333,
  "raw": 10,
  "min": 0,
  "max": 30
}

The scale of the score is not really a matter, I wanted to know why the scores are 'rounded up' to 50%, and Is there something I can do to get the actual scores. I've got the same result when I tried to upload the zip file attached and launched it in SCROM cloud.