QA – Basics of Percentages
Percentages are a good way of comparing things. Percentages simply mean “per 100”.
So, if we say, ‘in future, 80% of engineers will be women’ it means that in the future, out of every 100 engineers, 80 will be women.
To convert a fraction into a per cent we have the following:
To convert any fraction to rate per cent, multiply it by 100 and put % sign, i.e.,
Similarly to convert a percentage into fraction, drop the per cent sign and divide the number by 100.
The given table can be used for quick calculations:
Fraction | %age | Fraction | %age |
---|---|---|---|
1/2/2016 | 50% | 1/9/2016 | 11.11% |
1/3/2016 | 33.33% | 1/10/2016 | 10% |
1/4/2016 | 25% | 1/11/2016 | 9.09% |
1/5/2016 | 20% | 1/12/2016 | 8.33% |
1/6/2016 | 16.66% | 1/13/2016 | 7.69% |
1/7/2016 | 14.28% | 1/14/2016 | 7.14% |
1/8/2016 | 12.50% | 1/15/2016 | 6.66% |
To find the percentage change:
Percentage Change =[(Final Value – Initial Value) / Initial Value] x 100
Example: 2 employees were added in a company of 18 employees. So, how many employees would be added to a company of 100 employees?
The addition would be = (2 * 100) / 18 = 200/18 = 100/9 = 11.11
Additional Formulae for Percentages:
Successive Percentage:
Final value = x(1 + (A/100)) (x + (b/100)) (1 + (c/100)) …….
If A x% more than that of B, then B is less than that of A by:
[ x/ (100 + x) * 100]%
If A is x% less than that of B, then B is more than that of A by :
[ x/ (100 – x) * 100]%