Question 530495
x = number of students 25 and under
y = number of students over 25
.
x + y = 8500
so
x = 8500 -y
.
y = 1/3x
so
x = 3y
.
substitute
.
x = 3(8500-x)
.
x = 25500 -3x
.
4x = 25500
.
x = 6375
.
8500-x = 2125
.
The number of students 25 and under is 6375.
.
The number of students over 25 is 2125.
.
The number of students over 25 = 2125/6375 = 1/3 the number of students 25 and under.
.
Done.