Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Re: If x is an integer, which of the following is a possible value of (x² [#permalink]

Show Tags

21 Aug 2015, 06:48

2

This post received KUDOS

x is an integer, which of the following is a possible value of (x^2 +2x – 7)/9? Used process of elimination A. -2.4 when this is multiplied by 9, x is not an integer B. 0.268 when this is multiplied by 9, x is not an integer C. 1.166 repeating when this is multiplied by 9, x is not an integer D. 4.555 repeating E. 8.125 when this is multiplied by 9, x is not an integer

Re: If x is an integer, which of the following is a possible value of (x² [#permalink]

Show Tags

21 Aug 2015, 07:14

1

This post received KUDOS

This question is actually testing the test taker's knowledge about property of number "9". Any number, which is not divisible by 9, if divided by 9, the remainder repeats after decimal infinetely. This property matches with option "D". It is 41/9, which after multiplied with 9 leaves 41. Hence forming a quadratic equation X^2+2x-48=0, whose factors can be derived -> X=-8 or X=6

If x is an integer, which of the following is a possible value of (x² [#permalink]

Show Tags

21 Aug 2015, 07:19

2

This post received KUDOS

Convert to fraction and multiply by 9, if you get an integer, then you've the solution. As only one answer is correct, if I prove one to be correct, I have the solution.

For repeating decimals - I tried in order - C) a = 1.166 10a = 11.666 -- i 100a = 116.6666 -- ii

ii - i 90a = 105 a = 105/90 a*9 = 105/10 = 10.5 - not an answer

D) x = 4.555 10x = 45.5555 9x = 41 x= 41/9 x*9 = 41 -- can be the answer

putting back in original equation we get x = 6,-8 as possible solutions. So this is the correct answer.

Rest of all can be tested simply by converting them into fractions.

If x is an integer, which of the following is a possible value of (x^2 +2x – 7)/9?

A. -2.4 B. 0.268 C. 1.166 repeating D. 4.555 repeating E. 8.125

Kudos for a correct solution.

GROCKIT OFFICIAL SOLUTION:

We don’t have to start plugging in. We know that when divided by 9, the remainder will be a number repeating to the right of the decimal place. Only choice (D) fits that description.
_________________

If x is an integer, which of the following is a possible value of (x^2 +2x – 7)/9?

A. -2.4 B. 0.268 C. 1.166 repeating D. 4.555 repeating E. 8.125

Kudos for a correct solution.

GROCKIT OFFICIAL SOLUTION:

We don’t have to start plugging in. We know that when divided by 9, the remainder will be a number repeating to the right of the decimal place. Only choice (D) fits that description.

As nominator is an integer and denominator equals to 9, their division will result either integer or the repeating decimal (A, B, E are out). Plus repeating decimal will be one digit long (eg 111... or 333... not 123123...) and right after the decimal point (C out).

Answer: D.

To elaborate further: we have \(\frac{integer}{9}\), don't get trapped by the expression x^2+2x-7. What is important here is that the numerator will be integer as x is an integer.

\(\frac{integer}{9}\) can be either an integer 18/9=2, 27/9=3 ... or repeating decimal of the form k.aaaa..., where k is an integer >=0 and a is <9. Only D offers such number.
_________________

If x is an integer, which of the following is a possible value of (x² [#permalink]

Show Tags

25 Oct 2015, 09:21

1

This post received KUDOS

a more rapid approach is understanding that x/9 will yield 0.xxxxxx repeating. Only D has this pattern, so D is the answer choice. if to try, we can pick up x=6, 36+12-7 = 41/9 and this is equal to 4.55555 repeating.

we can as well notice that in C, the repeating decimal is 1666666.., this is clearly 1/6, but from the given fraction, we cannot get to smth/6.

Re: If x is an integer, which of the following is a possible value of (x² [#permalink]

Show Tags

15 Oct 2017, 08:07

Bunuel wrote:

If x is an integer, which of the following is a possible value of (x^2 +2x – 7)/9?

A. -2.4 B. 0.268 C. 1.166 repeating D. 4.555 repeating E. 8.125

Kudos for a correct solution.

Short cut to this is the know number properties from the arithmetic section. Number not-nine is divided by nine, its digits repeat infinitely. Knowing this, focus on options c, d.

For option c, let x = 4. 16 + 8 - 7 /9 = 17/9 = 1 8/9 = 1.888; therefore, eliminate option d

let x = 6; 41/9 = 4 5/9 = 4.555 Thus, the answer is D) 4.555