Question

A candidate should score 45% marks of the total marks to pass the examination. he got 520 marks and fails by 20 marks. the total marks the examination are:

Answer 1

so pass marks is 520+20=540 .now 
 let the total marks of exam be'x'
then,
45%of x = 540
45/100*x=540
x=540*100/45
x=1200

Answer 2

Let the maximum marks is 'x'

Mark of candidate = 520

Less mark to pass = 20

then passing mark = 520 + 20

                               = 540

According to question,

Let the total mark as 'x'

45% of total mark = 540

⇒ 45% of 'x' = 540

$\implies\dfrac{45}{100}\times x=540\\\\\\\implies45\times x=540\times100\\\\\\\implies45\times x=54000\\\\\\\implies x=\dfrac{54000}{45}\\\\\\\implies x=1200$

Let us verify -

⇒ 45% of 1200 = 540

$\implies\dfrac{45}{100}\times1200=540\\\\\\\implies45\times12=540\\\\\\\implies540=540$

Here,

      LHS = RHS

Hence,

     It is verified

Therefore total marks of the examination is

45% of 'x'

= 45/100 × 1200

= 540