Average of marks obtained by 150 candidates in a certain examination is 50 . If average marks of pas

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The average of marks obtained by $150$ candidates in a certain examination is $50 .$ If the average marks of passed candidates is $55$ and that of the failed candidates is $25,$ what is the number of candidates who passed the examination?

A

$125$

B

$120$

C

$140$

D

$160$

Solution

Let the number of candidates who passed $=x$

According to question

$55 \times x+25(150-x)=150 \times 50$

$55 x-25 x=7500-3750=3750 / 30 \Rightarrow x=125$

Hence no of candidate who passed the exam $=125$

Standard 13

Quantitative Aptitude

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