Andy was at Level –1 and took the elevator to Level 21. How many levels did the elevator move upward?

Valentino starts with a population of 1,500 amoebas that increases 35% in size every hour for a number of hours, h. the expression 1,500(1+0.35)h finds the number of amoebas after h hours. which statement about this expression is true? a. it is the initial population raised to the growth factor after h hours. b. it is the sum of the initial population and the percent increase. c. it is the sum of the initial population and the growth factor after h hours. d. it is the product of the initial population and the growth factor after h hours.

Percent increase and decrease. original number: 45 new number: 18

Rounded to the nearest tenth, what is the value of x