Which of the following statements can be inferred from the

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Which of the following statements can be inferred from the data above?

I. The Klein family's annual income more than doubled from 1985 to 1995.
II. The Klein family's annual income increased by a greater amount from 1985 to 1990 than from 1990 to 1995.
III. The Klein family's average (arithmetic mean) annual income for the period shown was greater than $40,000.

A. I only
B. II only
C. I and III only
D. II and III only
E. I, II, and III

These question tend to waste my time a lot. Are there any clever strategies to solve them in 2/2.30 mins? Thanks
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by sanju09 » Sat Dec 26, 2015 5:03 am
Nina1987 wrote:Which of the following statements can be inferred from the data above?

I. The Klein family's annual income more than doubled from 1985 to 1995.
II. The Klein family's annual income increased by a greater amount from 1985 to 1990 than from 1990 to 1995.
III. The Klein family's average (arithmetic mean) annual income for the period shown was greater than $40,000.

A. I only
B. II only
C. I and III only
D. II and III only
E. I, II, and III

These question tend to waste my time a lot. Are there any clever strategies to solve them in 2/2.30 mins? Thanks
Process of elimination while working with each statement saves time and effort on such problems.

I. The Klein family's annual income more than doubled from 1985 to 1995.

In 1985, it was 25, and in 1995, it was just below 65. Clearly, it's more than double as compared to 1985. Hence, the statement (I) is correct. So, let's eliminate options that do not include (I). B and D get eliminated.

II. The Klein family's annual income increased by a greater amount from 1985 to 1990 than from 1990 to 1995.

Increase from 1985 to 1990 is 40 - 25 = 15, and increase from 1990 to 1995 is about 65 - 40 = 25. The statement (II) tells opposite of it. Hence, eliminate from the remaining options one that do include (II), (E) gets eliminated.

III. The Klein family's average (arithmetic mean) annual income for the period shown was greater than $40,000.

Rough estimation tells us that most of the readings are around 40 or fairly above 40. Hence, the average (arithmetic mean) annual income for the period shown will be greater than 40. Hence, only [spoiler](I) and (III) are correct.

Choose (C).
[/spoiler]


A. I only
B. II only
C. I and III only
D. II and III only
E. I, II, and III
The mind is everything. What you think you become. -Lord Buddha



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Quantitative Instructor
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by Nina1987 » Sat Dec 26, 2015 7:12 am
sanju09 wrote:

Rough estimation tells us that most of the readings are around 40 or fairly above 40. Hence, the average (arithmetic mean) annual income for the period shown will be greater than 40. Hence, only [spoiler](I) and (III) are correct.


pls can you elaborate on this point? thks

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by sanju09 » Sun Dec 27, 2015 1:16 am
Nina1987 wrote:
sanju09 wrote:

Rough estimation tells us that most of the readings are around 40 or fairly above 40. Hence, the average (arithmetic mean) annual income for the period shown will be greater than 40. Hence, only [spoiler](I) and (III) are correct.


pls can you elaborate on this point? thks


A quick rough summation of the 10 readings in the descending order would ensure the sum is more than 400 even when we haven't added them all; hence the average is more than 40.
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com