mathschallenge.net logo

Solid Encryption

Problem

Although your mathematics teacher tells excellent jokes, he can be particularly cruel. At the end of a lesson he hands out a small piece of paper to each student.

A cement mixer collided with a prison van...

31 51 02 51 81 90 91 02 91 10
81 50 10 91 11 50 40 02 51 20
50 51 41 02 80 50 21 51 51 11
51 12 02 60 51 81 91 90 42 02
50 50 41 80 10 81 40 50 41 50
40 30 81 90 31 90 41 10 21 91

Can you discover the punchline?

Problem ID: 9 (Aug 2000)     Difficulty: 2 Star

Show Problem & Solution