Question

What percent of Rs. 80 is Rs. 100?

Answer 1

Hint: First, we will assume the required percentage of some variable and then we will form the linear equation from the given numbers and the assumed variable. We will solve this using the percentage formula.

Complete step-by-step solution:
We will assume the required percentage as ‘x’.
We have to find the percentage of Rs. 80 of Rs. 100. We will use the condition that if ‘a’ percent of ‘b’ is ‘c’ then the required equation will be
\[ \Rightarrow \dfrac{a}{{100}} \times b = c\].
As we assumed above, ‘x’ is the percent of Rs. 80 of Rs. 100. So, ‘a’ will be ‘x’. ‘b’ will be 80 and ‘c’ will be 100.
Substituting the values in the above equation:
$\dfrac{x}{{100}} \times 80 = 100$
$\Rightarrow x = \dfrac{{100 \times 100}}{{80}}$
$\Rightarrow x = \dfrac{{10000}}{{80}}$
$\Rightarrow x = \dfrac{{1000}}{8}$
$\Rightarrow x = 125$%
So, 125 percent of Rs. 80 is Rs. 100.

Note: A percentage is a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign, "%". The percent value is computed by multiplying the numeric value of the ratio by 100.
We can solve this problem with another method.
We are asked to find what percent of Rs. 80 to Rs. 100. The percent is calculated to 100.
So, we will assume that 80 is divided into 100 parts.
Let's assume ‘a’ as the value of the divided part.
$a = \dfrac{{80}}{{100}}$
$a = \dfrac{4}{5}$
Now, the number of parts having the same value that gets 100 is the required percentage.
We will assume the required percent as ‘x’.
‘x’ parts of value equal to ‘a’ form 100. Then, we get
$x \times \dfrac{4}{5} = 100$
$x = 100 \times \dfrac{5}{4}$
$x = 125$%