GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 24 May 2019, 02:52 ### GMAT Club Daily Prep

#### 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. ### Request Expert Reply # If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

### Hide Tags

Manager  S
Joined: 02 Mar 2018
Posts: 66
Location: India
GMAT 1: 640 Q51 V26 GPA: 3.1
If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value  [#permalink]

### Show Tags

1
8 00:00

Difficulty:   35% (medium)

Question Stats: 76% (02:19) correct 24% (02:39) wrong based on 111 sessions

### HideShow timer Statistics

If $$3^{y + 1} + 3^{y − 2} + 3^{y − 3} = 85(3^{x + 5})$$, what is the value of y in terms of x?

A. x
B. x + 2
C. x − 2
D. x + 8
E. x − 8

Originally posted by gsingh0711 on 30 Jul 2018, 15:59.
Last edited by Bunuel on 30 Jul 2018, 21:23, edited 2 times in total.
Renamed the topic and edited the question.
Manager  S
Joined: 02 Mar 2018
Posts: 66
Location: India
GMAT 1: 640 Q51 V26 GPA: 3.1
Re: If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value  [#permalink]

### Show Tags

1
Explanation:

3y+1+3y−2+3y−3=85(3x+5)

⇒ 3y(31+3−2+3−3)=85(3x+5)

⇒ 3y(3+19+127)=85(3(x+5)) )

⇒ 3y(8527)=85(3(x+5))

⇒ 3y=27(3x+5)=33×3x+5

⇒ 3y=3x+8

⇒ y = x + 8

Answer: D.

I think, I deserve a kudus LoL
Math Expert V
Joined: 02 Aug 2009
Posts: 7686
If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value  [#permalink]

### Show Tags

4
gsingh0711 wrote:
If $$3y + 1 + 3y − 2 + 3y − 3 = 85(3x + 5)$$, what is the value of y in terms of x?

A. x
B. x + 2
C. x − 2
D. x + 8
E. x − 8

Poor question at the first look itself..

All the choices have coefficient of X and y same as y=X or y=X+2
But the two sides tell us that y has 9 as coefficient and X has 85*3, so can never be equal

$$3y + 1 + 3y − 2 + 3y − 3 = 85(3x + 5)........9y-4=255x+425.......9y=255x+429........y=85x/3 + 143/3...$$

If it is
Question is
$$3^{y + 1} + 3^{y − 2} + 3^{y − 3} = 85(3^{x + 5})................... 3^{y-3}(3^4+3+1)=85(3^{X+5}................... 3^{y-3}*85=85*3^{X+5}...................... 3^{X+5}=3^{y-3}$$

Equating the powers
x+5=y-3.......y=x+8

D
_________________
Math Expert V
Joined: 02 Sep 2009
Posts: 55272
Re: If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value  [#permalink]

### Show Tags

1
chetan2u wrote:
gsingh0711 wrote:
If $$3y + 1 + 3y − 2 + 3y − 3 = 85(3x + 5)$$, what is the value of y in terms of x?

A. x
B. x + 2
C. x − 2
D. x + 8
E. x − 8

Poor question at the first look itself..

All the choices have coefficient of X and y same as y=X or y=X+2
But the two sides tell us that y has 9 as coefficient and X has 85*3, so can never be equal

$$3y + 1 + 3y − 2 + 3y − 3 = 85(3x + 5)........9y-4=255x+425.......9y=255x+429........y=85x/3 + 143/3...$$

Yes. The formatting in the question as well in the "solution" was all messed up. I guess the guy just copy pasted both from some source without checking. I fixed it.
_________________
Manager  S
Joined: 02 Mar 2018
Posts: 66
Location: India
GMAT 1: 640 Q51 V26 GPA: 3.1
Re: If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value  [#permalink]

### Show Tags

Bunuel wrote:
chetan2u wrote:
gsingh0711 wrote:
If $$3y + 1 + 3y − 2 + 3y − 3 = 85(3x + 5)$$, what is the value of y in terms of x?

A. x
B. x + 2
C. x − 2
D. x + 8
E. x − 8

Poor question at the first look itself..

All the choices have coefficient of X and y same as y=X or y=X+2
But the two sides tell us that y has 9 as coefficient and X has 85*3, so can never be equal

$$3y + 1 + 3y − 2 + 3y − 3 = 85(3x + 5)........9y-4=255x+425.......9y=255x+429........y=85x/3 + 143/3...$$

Yes. The formatting in the question as well in the "solution" was all messed up. I guess the guy just copy pasted both from some source without checking. I fixed it.

I think system failed the read the raised to the powers and that is why formatting looked messed up.
Director  V
Joined: 27 May 2012
Posts: 787
Re: If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value  [#permalink]

### Show Tags

1
gsingh0711 wrote:
If $$3^{y + 1} + 3^{y − 2} + 3^{y − 3} = 85(3^{x + 5})$$, what is the value of y in terms of x?

A. x
B. x + 2
C. x − 2
D. x + 8
E. x − 8

Dear Moderator,
Found this PS question , in the DS section, hope you will do the needful. Thank you.
_________________
- Stne
Math Expert V
Joined: 02 Sep 2009
Posts: 55272
Re: If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value  [#permalink]

### Show Tags

stne wrote:
gsingh0711 wrote:
If $$3^{y + 1} + 3^{y − 2} + 3^{y − 3} = 85(3^{x + 5})$$, what is the value of y in terms of x?

A. x
B. x + 2
C. x − 2
D. x + 8
E. x − 8

Dear Moderator,
Found this PS question , in the DS section, hope you will do the needful. Thank you.

___________________
Done. Thank you.
_________________
VP  D
Joined: 09 Mar 2016
Posts: 1283
If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value  [#permalink]

### Show Tags

gsingh0711 wrote:
Explanation:

3y+1+3y−2+3y−3=85(3x+5)

⇒ 3y(31+3−2+3−3)=85(3x+5)

⇒ 3y(3+19+127)=85(3(x+5)) )

⇒ 3y(8527)=85(3(x+5))

⇒ 3y=27(3x+5)=33×3x+5

⇒ 3y=3x+8

⇒ y = x + 8

Answer: D.

I think, I deserve a kudus LoL

gsingh0711 hey there thank you for your explanation To deserve kudos please make explanation clear and math friendly (explain with words step by step)  Use math formatting tools express exponent like this $$3^2$$ VP  D
Joined: 09 Mar 2016
Posts: 1283
If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value  [#permalink]

### Show Tags

chetan2u wrote:
gsingh0711 wrote:
If $$3y + 1 + 3y − 2 + 3y − 3 = 85(3x + 5)$$, what is the value of y in terms of x?

A. x
B. x + 2
C. x − 2
D. x + 8
E. x − 8

Poor question at the first look itself..

All the choices have coefficient of X and y same as y=X or y=X+2
But the two sides tell us that y has 9 as coefficient and X has 85*3, so can never be equal

$$3y + 1 + 3y − 2 + 3y − 3 = 85(3x + 5)........9y-4=255x+425.......9y=255x+429........y=85x/3 + 143/3...$$

If it is
Question is
$$3^{y + 1} + 3^{y − 2} + 3^{y − 3} = 85(3^{x + 5})................... 3^{y-3}(3^4+3+1)=85(3^{X+5}................... 3^{y-3}*85=85*3^{X+5}...................... 3^{X+5}=3^{y-3}$$

Equating the powers
x+5=y-3.......y=x+8

D

chetan2u can you please explain how from this $$3^{y-3}(3^4+3+1)=85(3^{X+5}$$ you got this $$3^{y-3}*85=85*3^{X+5}$$ ? what happened to this $$(3^4+3+1)$$ ? Math Expert V
Joined: 02 Aug 2009
Posts: 7686
Re: If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value  [#permalink]

### Show Tags

1
dave13 wrote:
chetan2u wrote:
gsingh0711 wrote:
If $$3y + 1 + 3y − 2 + 3y − 3 = 85(3x + 5)$$, what is the value of y in terms of x?

A. x
B. x + 2
C. x − 2
D. x + 8
E. x − 8

Poor question at the first look itself..

All the choices have coefficient of X and y same as y=X or y=X+2
But the two sides tell us that y has 9 as coefficient and X has 85*3, so can never be equal

$$3y + 1 + 3y − 2 + 3y − 3 = 85(3x + 5)........9y-4=255x+425.......9y=255x+429........y=85x/3 + 143/3...$$

If it is
Question is
$$3^{y + 1} + 3^{y − 2} + 3^{y − 3} = 85(3^{x + 5})................... 3^{y-3}(3^4+3+1)=85(3^{X+5}................... 3^{y-3}*85=85*3^{X+5}...................... 3^{X+5}=3^{y-3}$$

Equating the powers
x+5=y-3.......y=x+8

D

chetan2u can you please explain how from this $$3^{y-3}(3^4+3+1)=85(3^{X+5}$$ you got this $$3^{y-3}*85=85*3^{X+5}$$ ? what happened to this $$(3^4+3+1)$$ ? Hi..
3^4+3+1=81+3+1=85
So 3^4+3+1 is replaced with 85
_________________
Manager  S
Joined: 12 Sep 2017
Posts: 246
If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value  [#permalink]

### Show Tags

1
$$3^{y + 1} + 3^{y − 2} + 3^{y − 3} = 85(3^{x + 5})$$

$$3^{y + 1} ( 1 + 3^{− 3} + 3^{− 4}) = (5)(17)(3^{x + 5})$$

$$3^{y + 1} ( 1 + {1/27} + {1/81}) = (5)(17)(3^{x + 5})$$

$$3^{y + 1} ( {85/81}) = (5)(17)(3^{x + 5})$$

$$3^{y + 1} ( 85 * 3^{− 4}) = (85)(3^{x + 5})$$

y + 1 + ( - 4 ) = x + 5

y = x + 8

D

Originally posted by jfranciscocuencag on 10 Feb 2019, 21:22.
Last edited by jfranciscocuencag on 10 Feb 2019, 21:40, edited 5 times in total.
VP  G
Joined: 09 Mar 2018
Posts: 1004
Location: India
If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value  [#permalink]

### Show Tags

1
gsingh0711 wrote:
If $$3^{y + 1} + 3^{y − 2} + 3^{y − 3} = 85(3^{x + 5})$$, what is the value of y in terms of x?

A. x
B. x + 2
C. x − 2
D. x + 8
E. x − 8

$$3^y$$ [ 3 + 1/9 +1/27 ] = 85 $$(3^{x + 5})$$

take $$3^y$$ common

$$3^y$$ [ 85/27] = 85 $$(3^{x + 5})$$

$$3^y$$ = $$(3^{x + 8})$$

y = x+8

D
_________________
If you notice any discrepancy in my reasoning, please let me know. Lets improve together.

Quote which i can relate to.
Many of life's failures happen with people who do not realize how close they were to success when they gave up.
Intern  B
Joined: 20 Jan 2019
Posts: 2
Re: If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value  [#permalink]

### Show Tags

3^Y•3 + 3^Y•3^-2 + 3^Y•3^-3 = 85•3^X•3^5
3^Y ( 3 + 1/9 +1/27) =85•3^5•(3^X)
3^Y (85/27) = 85•3^5•(3^X)
3^Y = 3^3•3^5•3^X
Y= 3+5 +X
Y = X +8

Answer D Re: If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value   [#permalink] 24 Mar 2019, 04:53
Display posts from previous: Sort by

# If 3^(y + 1) + 3^(y − 2) + 3^(y − 3) = 85(3^(x + 5), what is the value

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.

#### MBA Resources  