User blog comment:Akrie/March 32nd Events & Updates~!/@comment-33658145-20160401041344/@comment-8222987-20160402090413

https://www.youtube.com/watch?v=u9wZVGateo8

Squire Gaming posted a video on this and from his attempts shows that the chance is approximately 1/10 (given if you see both treasures as one)