Percentage question

Question

Hi, I have a stupid question for you regarding percentage problems. Whenever a question mentions a percentage (%20 for example), when do you need to say that is: 1.20 or 0.20? I still do not get it because in some problem we need to say 0.20 and in others we need to say 1.20, and why 1.20?

Someone please explain it to me. Thank you very much.

smily_buddy · Answer

The best way i think is to take tha base as 100

and then 20% increase should be 120%. It is easier to calculate this way!!!

Any other ideas are welcome...

diegmat · Answer

It really depends on what the question is asking. For example if the question asks â€œA bank account pays annual interest of 20% (compounded annually), how much interest would a bank account with $100 in it earn in one year?â€

Priyah · Answer

Its simple really if you dont get confused with all the words.

20% is 20/100 =0.2 (when the base is 1)
Depending on whether we are taking of   increase   or   decrease  , we  add  or  minus  the amt from 1.

For e.g,
When I say 20%   increase   in quantity A, new quantity= 1.2 A 
 20%   decrease    in quantity A, new quantity=0.8 A

However, if I say B's salary is 20% of C's salary, then
B=0.2C
Note that this means that if I   decrease   C's salary by 80%, I get B's salary.

Hope this helps.

unzanthinking · Answer

Example

$20 earn 10% interest this year

To find the interest
$20 * .10 = $2

$20 Beginning Balance + $2 Interest = $22 Ending Balance

To arrive at the ending balance, we need to include the $20 in the calculation.

The easiest way is:
$20 * 1.10 = $22

The rest depends on what the question is asking.

Percentage question

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