GMAT Math

A report consisting of 2600 words is divided into 23 paragraphs . A 2-papragraph preface is then added to the report. Is the average number of words per paragraph for all 25 paragraphs less than 120?

1) each paragraph of the preface has more than 100 words.

2) each paragraph of the preface has fewer than 150 words

A report consisting of 2600 words is divided into 23 paragraphs . A 2-papragraph preface is then added to the report. Is the average number of words per paragraph for all 25 paragraphs less than 120? let x be the number of words in the 1st paragraph and y be the number of words in the 2nd paragraph . Then total number of words = 2600 + x + y . The question reads the average number of words per paragraph for all 25 paragraphs less than 120? Implies total words = 2600+ x + y < 25*120. Rephrased question

Is x + y < 400 ?

1) each paragraph of the preface has more than 100 words.

x + y > 200, x + y can be 201 or 601. Hence the question Is x + y < 400 ? cannot have a definite answer.Insufficient!

2) each paragraph of the preface has fewer than 150 words

x + y < 300; => x + y < 400, hence Sufficient!

Answer B

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