Question

Find the value of 20% of 2 from the following:-
A. 20
B. 4
C. 0.4
D. 0.2

Answer 1

Hint: Percent (%) is made up of two words 'per = each/every' and 'cent = hundred'. It gives the rate of the values of two quantities when the value of the second quantity is 100.
'a% of x' means divide x into 100 equal parts and take 'a' number of parts out of them.
'a% of x' is equal to $\dfrac{a}{100}\times x$ .

Complete step-by-step answer:
Using the definition of 'percentage', 20% of 2 is equal to $\dfrac{20}{100}\times 2$ .
If we multiply the numerators and divide by 100, we get:
 $\dfrac{20}{100}\times 2=\dfrac{40}{100}=\dfrac{4}{10}=0.4$
Therefore, the correct answer option is C. 0.4.

Note: It is easier to calculate 100%, 10% and 1% of any number simply by moving the decimal point one/two steps to the left.
100% of x = x.
10% of x = $\dfrac{x}{10}=0.1x$ .
1% of x = $\dfrac{x}{100}=0.01x$ .
Therefore, 20% of 2 = 10% of 2 + 10% of 2 = 0.2 + 0.2 = 0.4.
34% of 65 = (10% of 65) × 3 + (1% of 65) × 4 = 0.65 × 3 + 0.065 × 4 = 1.95 + 0.260 = 2.21.
a% of b is equal to b% of a.
Ratio is the general name for all the rates, any value of the second quantity.
Some specific rates are:
Per cent (%): where the value of the second quantity is 100.
Per mille (‰): where the value of the second quantity is 1000.
Per million: when the value of the second quantity is 1 million.