Question

60 Students appeared in an examination. On average, they get 45 marks. Those who passed got an average 55 marks and those who failed got 30 marks. Find out the number of passes.​

Answer 1

Let the number of the passed candidates=x.

Then the number of the failed candidates=120-x.

Now the total of the marks obtained by 120

\sf \: candidates=60×45=2700candidates=60×45=2700

The total of the marks obtained by passed

\sf \: candidates=(60−x)×30=2700candidates=(60−x)×30=2700

The total of the marks obtained by passed

\sf \: candidates=55×x=55x. and candidates=55×x=55x. and

the total of the marks obtained by failed

\sf \: candidates=(60−x)×30=2700candidates=(60−x)×30=2700

Then the total=39x+(120−x)×15=4200

\sf⟹24x=2700−1800⟹24x=2700−1800

\implies \sf \: x=100⟹x=100

So the number of passed candidates=100.