you have 50 students one day and 70 the next what is the percentage increase

Answer 1

I think it is 20%. Because a each tenth is 10% and 70-50 equals a 20% increase. so i'm sure its 20%

Answer 2

Sorry, but Environmental is wrong.

70-50 = 20 student increase

20/50 = 0.4 = 40% increase