Quantitative Aptitude – Percentage
A very important chapter for competitive exam is Percentage. Every competitive exam question paper must have at least one question from this topic. And so many other questions which are related to this chapter. So, you should learn this chapter very carefully.
Percentage is related to fraction. So if you do not know what fraction is or if you need to brush up your previous knowledge of fraction, then first learn “Fraction“.
But, if you are comfortable with fraction then we can start our lesson.
What is Percentage ?
Definition: Percentage is the number per hundred.
Let’s explain this,
- 50% means 50/100 or 50 per 100.
- 25% means 25/100 or 25 per 100.
- 10% means 10/100 or 10 per 100.
Examples
Suppose a hotel has 100 rooms in it. Out of those rooms 50 rooms are vacant and other rooms are booked. So the percentage of vacant room in that hotel is 50/100. That means 50% room of that hotel is vacant.
Similarly if 25 rooms were vacant in that hotel, then we can say that 25% rooms are vacant.
Now if the hotel has 80 rooms in it and out of those 80 rooms 60 rooms are vacant, then what will be the percentage of vacant rooms?
To calculate this we need formula. And formula for calculating percent is given below.
What are the Formulas ?
Suppose we want to find 50% of 100. The formula to find this is,
Percent
————— X Number = Percentage
100
Therefore, 50% of 100 is,
50
——– X 100 = 50
100
So, 50% of 100 is 50.
Using this formula we can also find out “50 is how much percent of 100?“.
Percent
————— X Number = Percentage
100
putting values,
Percent
————— X 100 = 50
100
Therefore, Percent = 50
So, 50 is 50% percent of 100.
And also we can also find out “If 50% of a number is 50 then what is the number?“.
Percent
————— X Number = Percentage
100
putting values,
50
——— X Number = 50
100
After calculating, Number = 100
If 50% of a number is 50 then the number is 100.
Now back to the hotel room problem. We asked that if a hotel has 80 rooms in it and out of those 80 rooms 60 rooms are vacant. Then what will be the percentage of vacant room.
Formula for this is,
Percent
————— X Number = Percentage
100
putting values,
Percent
————— X 80 = 60
100
Therefore, Percent = 75%
So, If 60 rooms out of 80 rooms are vacant in the hotel, it means 75% rooms are vacant in that hotel.
So, we hope you can now do any kind of problem using the above rule. If you need any farther help on this chapter, then please let us know. We will discuss on those problems here in www.AptitudeTricks.com.