Percents of Increase/Decrease?

Question

Having a little problem figuring out how to make percents out of these..

$2 to $3

4 ft to 5 ft

9 m to 12 m

15 lb to 18 lb

I'm having trouble calculating the percent increase and descrease of these..

Answer 1

Take the difference between the initial and final amounts, and divide that by the initial amount. That will give you a decimal. Move the decimal point two places to the right ( that is, multiply by 100) to get the percent increase.

Answer 2

1/3 x 100= 33.33333..... %
1/4x100=25%
3/9 x 100= 33.33333% and so on
3/15 x 100=20%