Thread: A simple formula to count percents?

Originally Posted by Liza88

I'm really bad in counting percents. Can you explain me a simple way to solve the following problem. I'd appreciate it a lot

- The population of a city raised each year X times compared to the last year. This happened ten years (ten times) and in the end the population was twice as large as in the beginning.

How will I find out what the X is ?

You must have heard of GP

nth term of GP( geometric progression)
... A is first term , r is the Common ratio

Let initial population is P
So 10 th year the population is


Hence

Oops Just noticed you wanted percentage

I am giving you a sample
Percentage of any value x in a total quantity (x+y) is given by



.............................................
For finding percentage increase after 10 years