Ian has three pets: Barnum the cat, Bailey the cat, and Daisy the dog,

[quote="LighthousePrep"]Hi,

The best way to attack this question is to dive in.

With the information given, we know that X is 1001 (361,361 divided by 361).

Now, we know that to get a product of 1001, we need three numbers that are close to 10 (because 10*10*10 = 1000).

Playing around, we can find that the ages of the three pets are 7, 11, and 13 (7*11*13=1001).

(1) clearly tells us Daisy's age.
(2) narrows it down to two options, but doesn't solve the problem.

Thus, (1) alone is sufficient. A.

Hope this helps! Good luck studying!



Hi @Bunnel,
Please explain.I got the answer as E.
In statement A,we are told that dog's age is not 10.Thus, it can be 13,7,11.
How can A be sufficient

Hi All,

Although the original author of this question did not put in the restriction that the ages are all INTEGERS, it appears that that is the "intent" of the question. The questions on the Official GMAT are always carefully worded though (to remove this type of ambiguity).

Using prime factorization, we're meant to deduce that the ages of the pets are 7, 11 and 13 (in some order). We're asked for Daisy's age.

Fact 1: Daisy is not yet 10.

This means that she's YOUNGER than 10 and there's only one value that fits: 7
Fact 1 is SUFFICIENT

Fact 2: The sum of the digits in Barnum's age is EVEN.

This means that Barnum is either 11 or 13. In either situation, Daisy could be EITHER of the other two ages.
Fact 2 is INSUFFICIENT

Final Answer:

GMAT assassins aren't born, they're made,
Rich

Hi Rich,

Thank you so much for your explanation. Just one question:

Is the math shortcut 361,361/361 = 1,001 (or 421,421/421 = 1,001 or any of the like) one we should know for the GMAT

I´ve been studying for this exam for long and this is the first time I see it. I think this question could not be answered if one didn´t know about this math shortcut. I am asking this especially since this is not an official question.

Thank you so much

Hi minwoswoh,

In answer to your immediate question - NO, you don't have to have this specific pattern memorized. However, the GMAT IS a test that is based heavily on patterns, so your ability to spot, evaluate or deduce that a pattern occurs in a question can significantly improve your chances of answer the question correctly AND quickly.

For the sake of argument, how much TIME would it really take you to figure out that 361,361/361 = 1,001? Be honest. If you had to perform that calculation by hand, how long would it take? Certain GMAT questions require a bit more 'work' from you, so you shouldn't be surprised when you have to put pen to pad and perform a calculation. The truth is that while that specific calculation might "look" scary, it's NOT a difficult calculation. Business Schools expect you to stay calm and not 'get upset' by weird-looking numbers, so you're going to face some questions on the GMAT that include that type of 'psychological aspect.'

GMAT assassins aren't born, they're made,
Rich

Hi Rich,
Thank you so much for your answer. Yes, I understand that the GMAT is heavily biased on patterns. That´s why I always try to memorize patterns that come up often (this was not the case, since it was the first time I saw it...)

Regarding to your specific question: For the sake of argument, how much TIME would it really take you to figure out that 361,361/361 = 1,001? Be honest
It took me a while, to be honest... I wish I had been faster

Thanks again!

Hi minwoswoh,

To clarify, I'm not asking how long you stared at the calculation or thought about it (or attempted it in your head) - I'm asking about the actual PHYSICAL calculation itself. How long does it take to write it on the pad and perform the calculation?

If THAT part of the process is taking you a long time, then it might be that you need to put in some repetitions on doing standard arithmetic work (add, subtract, multiply, divide, simplifying fractions, etc.).

GMAT assassins aren't born, they're made,
Rich

x*361 = 361361.
x = 1001.
Factorize x, we get 1001 = 7*11*13.

From S1:

Dog's age is less than 10.
It has to be 7.
SUFFICIENT.

From S2:

Sum of age is even.
Can be 11 or 23.
INSUFFICIENT.

A is the answer

are you considering ages to be integer ?

Yes, I considered ages as integers.

Posted from my mobile device

Let the age of Barnum = a
age of Bailey = b
age of Daisy = d
Constraint: a,b,d > 1, a•b•d =x
Asked Daisy’s age (d)=?

x= 361,361/361= 1001
.: a•b•d= 1001 = 7•11•3 (in no particular order for a,b and d)

(St1) Daisy is not yet 10yrs old—> so d <10 . Now, only 7 in the product of the ages is less than 10. so Daisy’s age is 7yrs
(Suff.)

(St2) The sum of digits of Barnum’s (a) age is even
The only ages with sum digit Even is (11 or 13),so if a=11yrs ,then (b=13 ,d=7) or (b=7 ,d=13). Daisy’s age is 7or13 yrs

Again, if a=13yrs,then (b=11 ,d=7) or (b=7 ,d=11). Daisy’s age is 7 or 11yrs
different ages for (d)
(not sufficient)

Answer (A)

Posted from my mobile device

Maxirosario2012
General rule ages are always integer because I cannot tell my age is 12.5 years

+1

How do we come to the conclusion that we are dealing with integers? For GMAT, you guys always say that we can not take this for granted unless we are told we are dealing with integers.

Answer is obviously E.

abc = x
x * 361 = 361 361
x = 1001

7, 11, 13 fits.
5,5, 14, 13 also fits.

Half years of age are conventional answers to questions about age. How old are you? Five and a half. It is actually quite important for a child.