The following ple chart shows the number of students in a certain school. There are 2000 students in the school. Answer questions 21, 22 and 23 from the pie chart. Grade 1 30% Grade 3 20% Grade 4 15% 21. The number of students in grade 1 is 22. The number of students in grade 3 is 23. The number of students in grade 4 is