It is currently 21 Nov 2017, 21:15

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# If the square root of the product of three distinct positive

Author Message
Retired Moderator
Joined: 05 Jul 2006
Posts: 1749

Kudos [?]: 443 [0], given: 49

If the square root of the product of three distinct positive [#permalink]

### Show Tags

10 Aug 2009, 10:59
1
This post was
BOOKMARKED
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 100% (03:13) wrong based on 2 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If the square root of the product of three distinct positive
integers is equal to the largest of the three numbers, what is the
product of the two smaller numbers?

(1) The largest number is 12.
(2) The average (arithmetic mean) of the three numbers is 20/3

Kudos [?]: 443 [0], given: 49

Senior Manager
Joined: 20 Mar 2008
Posts: 451

Kudos [?]: 135 [0], given: 5

Re: square root of a product [#permalink]

### Show Tags

10 Aug 2009, 11:19
B for me.

1. The product of the other two numbers must be 12, but are they 4x3 or 6x2? So Insuff.

2. Avg is 20/3, therefore the sume of the other two is 8. Only 6 & 2 fits both the criteria. Suff.

Kudos [?]: 135 [0], given: 5

Intern
Joined: 21 Jul 2009
Posts: 21

Kudos [?]: 2 [0], given: 0

Re: square root of a product [#permalink]

### Show Tags

10 Aug 2009, 12:08
D for me.

If x,y, z are the integers in increasing order, from the stem xy = z (largest integer)

1) Z = 12 i.e. xy [product of two smaller numebers] = 12. Suff

2) x+y+z = 20 and xy = z (from question stem) ; only values which hold true are 2, 6, 12. Suff.

Kudos [?]: 2 [0], given: 0

Senior Manager
Joined: 20 Mar 2008
Posts: 451

Kudos [?]: 135 [0], given: 5

Re: square root of a product [#permalink]

### Show Tags

10 Aug 2009, 12:18
D seems right, for some reason I was adding 4x3 & 6x2.

Kudos [?]: 135 [0], given: 5

Retired Moderator
Joined: 05 Jul 2006
Posts: 1749

Kudos [?]: 443 [0], given: 49

Re: square root of a product [#permalink]

### Show Tags

10 Aug 2009, 23:57
sqrt xyz = z therfore xyz = z^2 from st one if z^2 = 144 therfore xy = 12

st two

sum of three numbers = x+y+z = 20 but from question stem z = xy

therfore x+y+xy = 20 ie x(1+y)+y = 20 therfore x = 20-y/1+y

WE KNOW THAT ODD/EVEN CAN NEVER GIVE AN INTIGER THUS Y CAN NEVER BE ODD ie : if y is odd 20-y is odd and Y+1 IS EVEN AND THUS

x = 20-y/1+y WOULD BE A FRACTION ( BUT X IS A POSITIVE INTIGER)

THUS Y COULD BE {2,4,8,} ANY VALUE FOR Y > 8 WILL YIELD 20-Y/1+Y<1 ,THUS BLUGGING IN VALUES FOR Y WE SEE THAT ONLY 2 CAN YIELD A POSITIVE INTIGER X = 6

AND THUS Y = 2 AND Z = 12 .... SUFF

Kudos [?]: 443 [0], given: 49

Intern
Joined: 30 Jul 2009
Posts: 17

Kudos [?]: 11 [0], given: 4

Location: Danbury CT
Schools: Wharton, Columbia , Cornell, CMU , Yale
Re: square root of a product [#permalink]

### Show Tags

11 Aug 2009, 04:53
But if you look at the question itself it is asking the product of other two numbers.
(xyz)^1/2=Z

Z= 12 then (xy.12)^1/2 = 12 .. solving it xy = 12 _ Sufficient enough as you are able to determine the product of the rest of two numbers

I think statement 1 alone should be sufficient to answer the questions (which is to determine the product of other two numbers)
_________________

Kudos [?]: 11 [0], given: 4

Re: square root of a product   [#permalink] 11 Aug 2009, 04:53
Display posts from previous: Sort by