A percentage is a way to describe a part of a whole. The number of students in the 2nd grade is 112(x-10 = 122-10).
What are Percentages?
A percentage is a way to describe a part of a whole. such as the fraction 1/4 can be described as 0.25 which is equal to 25%.
To convert a fraction to a percentage, convert the fraction to decimal form and then multiply by 100 with the '%' symbol.
As it is given that the total number of students in the school is 500 students. Also, a few of the things are known, therefore, the number of students in different classes can be written as,
1. 17% of the total number of students are in 1st grade.
Number of students in 1st grade = 17% of total student = 0.17×500 = 85
2. 19% of the total number of students are in 4th grade.
Number of students in 4th grade class = 19% of total student = 0.19×500 = 95
3. The number of 3rd-grade students is 9 less than the number of 4th-grade students.
Number of students in 3rd-grade class
= (Number of students in 4th-grade class) - 9
= 95 - 9 = 86
4. The number of 2nd-grade students is 10 less than the number of 5th-grade students.
Let the number of students in 5th grade be x, therefore,
Number of students in 2nd-grade class
= Number of students in 5th-grade class - 10
= x-10
Total number of students = 1st grad + 2nd grade + 3rd grade + 4th grade + 5th grade
500 = 85 + (x-10) + 86 + 95 + x
500 = 266 + 2x - 10
244 = 2x
x = 122
Thus, the number of students in the 2nd grade is 112(x-10 = 122-10).
Learn more about Percentages:
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