the number of students at a high school was decreased by 30% to 420 after the senior students graduated. How many students were there before the decrease?

Question

the number of students at a high school was decreased by 30% to 420 after the senior students graduated. How many students were there at the high school before the decrease?

 

Answer 1

A 30% decrease means that 420 is 70% of the original number N.

 

420 = 0.70N

 

N = 420/0.70 = 600