The number of students in Kylie's class is 50. In a particular test, ten students scored 90 marks, 15 scored ten marks fewer than the first ten students, and the rest scored 60 marks each. What are the average marks for the whole class?
How many marks did the first ten students score? ** The total marks for the first ten students are 90 * 10 = <<90*10=900>>900 marks
How many marks did the second ten students score? ** The 15 students who scored ten marks fewer than the first ten had 90 - 10 = 80 marks each.
How many marks did the second ten students score? ** The total marks for the following 15 students are 15 * 80 = <<15*80=1200>>1200 marks.
How many students scored above 60? ** The total number of students who scored above sixty is 10 + 15 = <<10+15=25>>25.
How many students scored 60? ** If 50 students were present in the class, those who scored sixty are 50 - 25 = <<50-25=25>>25.
How many marks did the 25 students score? ** If 25 students scored 60, then their total marks are 60 * 25 = <<60*25=1500>>1500 marks.
What is the total number of marks for the whole class? ** The whole class scored a total of 1500 + 1200 + 900 = <<1500+1200+900=3600>>3600 marks.
What is the average for the class? ** The average for the class is 3600 / 50 = <<3600/50=72>>72 marks.
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