# Can't find percentage increase.

• Oct 9th 2011, 09:41 AM
Mathsworld
Can't find percentage increase.
So I got this problem

Original Amount is 20 the new amount is 50

I need to find the percentage increase I usually use this method.

First find the increase from the original amount which is 30 (50-20)

Then 30/20 = 1.5

Then 1.5 * 100 = 150%

Now that does not seem to be the right answer as I check my answer by going vice versa how shall I do this?(Evilgrin)
• Oct 9th 2011, 10:04 AM
skeeter
Re: Can't find percentage increase.
an increase from 20 to 50 is a 150% increase.
• Oct 9th 2011, 10:38 AM
FrameOfMind
Re: Can't find percentage increase.
Your answer is right, what do you mean it doesn't seem to be right by going vice versa?

Remember that it is a 150% increase, but 50 is 250% of 20 (i.e. 100% + 150% increase).

$\displaystyle 20 + 150\% = 20 + 1.5(20) = 2.5(20) = 50$

$\displaystyle \frac {50}{2.5} = \frac {50}{\frac {5}{2}} = \frac {50}{1} * \frac {2}{5} = \frac {100}{5} = 20$
• Oct 9th 2011, 01:01 PM
Mathsworld
Re: Can't find percentage increase.
oh maybe a i checked it wrong I usually use the percentage Multiplier to check my answers.