Answer:
The previous number of students are 350.
Step-by-step explanation:
Let the number of students be 100x.
[tex]\frac{100+30}{100}[/tex]x = 455
Simplify.
[tex]\frac{130}{100}[/tex]x = 455
Find x.
[tex]\frac{100}{100}[/tex]x = [tex]\frac{100}{130}[/tex] × 455
Simplify.
x = 350