The second question of Tianjin senior high school entrance examination mathematics 18 is not difficult. According to relevant public information, in Tianjin, the difficulty of mathematics in the senior high school entrance examination itself is not particularly high, which is medium compared with the whole country. When the teacher gives a question, 10 asks the 20th question, and the percentage statistics will be made according to the students' difficulty in learning mathematics at ordinary times. The difficulty is about 40%, so the second question of 18 is not difficult.