Answer: 15
Explanation:
90 units divided 6 cases equals 15
I believe they were walked to the guillotine and told to kneel at the head of it. They would then be executed while people watched. It was brutal in that time.
Okinawa was one of the largest single battles in the pacific and also the bloodiest, It would see mass use of Kamikazes, artillery and mass banzai charges, it would ultimately be one of the key arguments against an invasion of Japan.
(PS sorry if this is too lengthy)