statistics

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

p.s: Can you please post DS questions here -> https://www.beatthegmat.com/data-sufficiency-f7.html and PS questions here -> https://www.beatthegmat.com/problem-solving-f6.html