In a school there are 122 grade 8s, 105 grade 9s, 134 grade 10s, 109 grade 11s, 90 grade 12s. Express Each Class as a percentage of the whole school.

Add up the numbers to find the total number of students in the whole school.

Divide the number in each class by the total. Multiply the decimal answer by 100 to get the percent.

Decide whether the pair lines is parallel,perpendicular 3x+5y=6 ,3x+3Y=10

To express each class as a percentage of the whole school, you need to find the total number of students in the school and then calculate the percentage for each grade.

To get the total number of students, you add up the number of students in each grade:
Total number of students = 122 + 105 + 134 + 109 + 90 = 560

To calculate the percentage for each grade, divide the number of students in each grade by the total number of students and multiply by 100.

For Grade 8:
Percentage = (Number of Grade 8 students / Total number of students) * 100 = (122 / 560) * 100 ≈ 21.79%

For Grade 9:
Percentage = (Number of Grade 9 students / Total number of students) * 100 = (105 / 560) * 100 ≈ 18.75%

For Grade 10:
Percentage = (Number of Grade 10 students / Total number of students) * 100 = (134 / 560) * 100 ≈ 23.93%

For Grade 11:
Percentage = (Number of Grade 11 students / Total number of students) * 100 = (109 / 560) * 100 ≈ 19.46%

For Grade 12:
Percentage = (Number of Grade 12 students / Total number of students) * 100 = (90 / 560) * 100 ≈ 16.07%

So, the percentages for each grade are approximately:
Grade 8: 21.79%
Grade 9: 18.75%
Grade 10: 23.93%
Grade 11: 19.46%
Grade 12: 16.07%