Question
The average mark obtained by 150 candidates in a certain
examination is 45. If the average marks of passed candidates are 55 and that of the failed candidates is 25, then what is the number of candidates who passed in the examination?Solution
According to question, => 55 × x + 25 × (150 − x) = 150 × 45 => 55x + 3750 – 25x = 6750 => x = 100
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