In 2003, due to the impact of SARS, the turnover of the catering industry in Nanjing in May was 350 million yuan, down 30% from the same period in 2002, and in May 2003, the Nanjing City
3.5÷(1-30%)-3.5
=3.5÷70%-3.5
=5-3.5
=150 million yuan
Answer: The turnover of the catering industry in Nanjing in May 2003 was 150 million yuan less than that of the same period in 2002.