In a pre-test paper for a course,

Student A scored 50% and student B scored 70%.

After the course, they sat for the post-test paper. They both scored 100%.

However, there is only 1 prize and the course organizer decided to give it to Student A.

Both students did not know their marks for both tests and it was easily assumed that Student A probably scored higher than Student B.

What are your thoughts about this?