Question

The average marks obtained by 75 students was 30. If the average of marks of passes candidates was 45 and that of failed candidates was 20, the number of candidates who passed the examination?

Answer 1

Given

The Total Number of student=75

The average of 75 students=30

Let

The total number of passed students be X

The total number of failed students be 75-x

A.T.Q

==>45×X+(75-X)×20=75×30

==>45X+1500-20X=2250

==>25X=2250-1500

==>25X=750

==>X=30

Hence,

The number of passed students=>30

Answer 2

$\huge\mathbb{\underline{\underline{Solution:-}}}$

⭐The average marks obtained by 75 students was 30. If the average of marks of passes candidates was 45 and that of failed candidates was 20, the number of candidates who passed the examination?

$\huge\mathbb{\underline{\underline{Answer:-}}}$

☑ 30 Students were passed.

✒$\huge\mathbb{\underline{\underline{Solution:-}}}$

The total score of 75 students = 75×30 = 2250

Let P be the no.of passed students,

So the failed students are (75-P)

=> P×45+ (75-P)×20 = 2250

=> 45P + 1500 - 20P =2250

=> 25P = 2250 - 1500

=> 25P = 750

=> P = 750/25

=> P = 30

So, 30 student were passed.

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