25. Percentage Applied

 

25. Percentage Applied

Learn and Remember :

1. Per cent means per hundred. Percentage is denoted by the symbol '%'.

 e.g. 15% means 15 out of 100.

2. 30% of x' means the proportionate value out of x, as 30 out of 100.

 e.g. 30% of 200 = 200 x 30⁄100= 60.

3. To convert a given fraction into percentage, multiply or divide the numerator and the denominator of the fraction by the same non-zero number to make the denominator 100.

e.g. 1)  ²⁄₂₅  = ^{2 × 4}⁄_{25× 4}  = ⁸⁄₁₀₀ =8% 

2)   ³⁶⁄ ₄₀₀  = ^{36 ÷4}⁄_{400÷ 4} = ⁹⁄₁₀₀ = 9%

4. Observe the percentages and the corresponding fractions :

100% = ¹⁄₁,  

50% = ¹⁄_2,    

25% =¹⁄₄ ,    

12¹⁄₂% = 1⁄8,    

6¹⁄₄% = 1⁄16,     

20% =¹ ⁄₅ ,    

10% = ¹⁄₁₀       

5% = ¹⁄₂₀ 

5. (i) If x is a% more than y, then y is  ^{100 ×a}⁄_{100 + a} % less than x.

 (ii) If x is a % less than y, the y is ^{100 × a}⁄_{100 - a % more than x.}