## Steps involved in finding a percent of a given number

Step I– Obtain the number, say x.

Step II– Obtain the required percent, say P %.

Step III– Multiply x by P and divide by 100 to obtain the required P % of x
i.e.,                        P% of x = $$\frac{ P}{ 100}$$ * x

## Illustrative Examples

Example 1: Find
(i)  30% of Rs 180            (ii) 13% of Rs 6500            (iii) 16% of 25 litres
Solution.   We know that P% of x is equal to $$\frac{ P }{ 100}$$ * x. So, We have

(i) 30% of Rs 180 = Rs ( $$\frac{ 30 }{ 100}$$ x 180) = Rs 54

(ii) 13% of Rs 6500 = Rs ( $$\frac{ 13 }{ 100}$$ x 6500 ) = Rs 845

(iii) 16% of 25 litres = Rs ( $$\frac{ 16 }{ 100}$$ x 25) = 4 litres

Example 2: If 23% of a is 46, then find a.

Solution. We have,

23% of a = $$\frac{ 23 }{ 100}$$ x a.

But, 23% of a is given as 46.

Therefore,   $$\frac{ 23 }{ 100}$$ x a => a = 46 x $$\frac{ 100 }{ 23 }$$

=> a = 200

Example 3: 72% of 25 students are good at Mathematics. How many are not good at it?

Solution. We have,

Number of students who are good at Mathematics

= 72% of 25

= $$\frac{ 72 }{ 100}$$ x 25 = 18