Quantitative Aptitude Ques 178

Question: The average of marks obtained by 120 candidates in a certain examination is 35. If the average marks obtained by passed candidates are 39 and those of the failed candidates are 15, then what is the number of candidates who passed the examination?

Options:

A) 100

B) 120

C) 150

D) 140

Show Answer

Answer:

Correct Answer: A

Solution:

  • Let the number of candidates who passed the examination be x. According to the question, $ 39\times x+15,(120-x)=120\times 35 $

$ \Rightarrow $ $ 39x+1800-15x=4200 $

$ \Rightarrow $ $ 24x=2400 $
$ \Rightarrow $ $ x=100 $