Question

The number 0.05 is how many percent of 20?

Answer 1

Hint: Here, we will proceed by using the formula to determine the percent of any number i.e., a percent of b is given by $\left( {\dfrac{a}{{100}}} \right) \times b$. In this problem, we are given with a percent of b equal to 0.05 where b=20 and we have to find the value of unknown a.

Complete step-by-step answer:

Given number is 0.05

Let x percent of 20 is the number 0.05

As we know that a percent of b is given by $\left( {\dfrac{a}{{100}}} \right) \times b$

Similarly, x percent of 20 = $\left( {\dfrac{x}{{100}}} \right) \times 20$

Also, x percent of 20 = 0.05
$ \Rightarrow \left( {\dfrac{x}{{100}}} \right) \times 20 = 0.05$

By taking 20 and 100 from the LHS to the RHS of the above equation, we get
$
   \Rightarrow x = \dfrac{{0.05 \times 100}}{{20}} \\
   \Rightarrow x = \dfrac{5}{{20}} \\
   \Rightarrow x = \dfrac{1}{4} \\
   \Rightarrow x = 0.25{\text{ percent}} \\
 $

Therefore, 0.25 percent of 20 is equal to the number 0.05.

Note: In this particular problem, we have written $\left( {\dfrac{x}{{100}}} \right) \times 20 = 0.05$ equal to $x = \dfrac{{0.05 \times 100}}{{20}}$ because when 20 (present in the numerator) which is getting multiplied in the LHS is taken to the RHS then 20 will be in division (will occur in the denominator) and also when 100 which is in division (present in the denominator) in the LHS is taken to the RHS then 100 will be multiplied in the numerator.