In order to prepare for the operation test of physical chemistry experiment in grade three, a school conducts simulation training for grade three students. There are four different operation experimen

(1) Draw a tree:

As shown in the figure, there are 16 possibilities for a classmate to draw lots;

(2)∵ Xiao Zhang draws two better experimental questions prepared by the subjects at the same time in four situations: 1B, 1C, 2B and 2C * * *.

∴ The probability that he draws a better experimental problem prepared by two subjects at the same time is 4 16 = 1 4.