Inspector Remorse had a difficult year in 2004. A crime wave in Camford meant that he had $20\%$ more cases to solve than in 2003, but his success rate dropped. In 2003, he solved $80\%$ of his cases, but in 2004 he solved only $60\%$ of them. What was the percentage change in the number of cases he solved in 2004 compared with 2003?
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
This problem is taken from the UKMT Mathematical Challenges.