Percentage

Raj = 100 then Raj = 80.

Raj more by 100 – 80 = 20

%more than Raj = 20/80 × 100 = 25

Rohan =. 0.80 Raj

1/ .80 = Raj

1.25 = Raj

Raj = 25 % Increase

Let Raj's height be $x$ .

Then, Rohan's height will be $0.8x$ ( $x - 0.2x = 0.8x$ )

The question asks By how many percentages is Raj's height bigger than Rohan's . What that basically means is that we should consider this proportion:

$\frac{0.8x}{x}=\frac{100\%}{?}$

From that we get:

$?=\frac{x\times100\%}{0.8x}=125\%$

And now we do the last step:

$= 125\% - 100\% = \boxed{25\%}$

to-ongs formula: x = (( 1 - .2 )inverse) - 1 =0.25 or 25 percent

Let Raj's Height be 100cm

Then, Rohan's height= $\frac{80}{100} \times 100 = 80cm$

$\%$ by which Raj's Height is more than Rohan's = $\frac{100-80}{80} \times 100 = \frac{20}{80}\times 100 = 25\%$

to-ongs formula: x = (( 1 - .2 )inverse) - 1 =0.25 or 25 percent