Author 
Message 
Manager
Joined: 06 Jul 2011
Posts: 213
Location: Accra, Ghana

Try this question on a friend posted to me on facebook [#permalink]
Show Tags
12 Apr 2012, 09:31
1+1+1+1+1+1+1+1+1+11+1+1+1+1+1*0=?
Some said the answer was 13, others say the answer is 0. Are there any Number Properties geniuses out there who can help with this crazy problem



Verbal Forum Moderator
Joined: 23 Oct 2011
Posts: 283

Re: Try this question on a friend posted to me on facebook [#permalink]
Show Tags
12 Apr 2012, 10:00
IMO answer is 13. As far as I can see, there are no tricks in this problem.
_________________
******************** Push +1 kudos button please, if you like my post.



Current Student
Joined: 12 Sep 2011
Posts: 900
Concentration: Finance, Finance

Re: Try this question on a friend posted to me on facebook [#permalink]
Show Tags
12 Apr 2012, 10:25
PEMDAS  Parenthesis, exponents, multiplication, division, addition, subtraction This is what "order of operations" that you should do all math work in. So first you'd do 1*0 = 0, then you'd add all the 1's together. I see the answer as 15, but only because you have 16 ones and 1 zero. The reason why this question is slightly confusing, is if you didn't know the order to do the work you would add up all the 1's, and then multiply by zero. Obviously, anything multiplied by 0 is 0, but in this case you adding to that 0 once that operation is completed. If you change the problem to (1+1+1+1...+1)*0, then you'd do the parenthesis first, and end up with 0 as your answer.
_________________
New to the GMAT Club? <START HERE>
My GMAT and BSchool Tips:
GMAT Club Premium Membership  big benefits and savings



Manager
Joined: 06 Jul 2011
Posts: 213
Location: Accra, Ghana

Re: Try this question on a friend posted to me on facebook [#permalink]
Show Tags
12 Apr 2012, 11:32
GMATLA wrote: PEMDAS  Parenthesis, exponents, multiplication, division, addition, subtraction
This is what "order of operations" that you should do all math work in.
So first you'd do 1*0 = 0, then you'd add all the 1's together.
I see the answer as 15, but only because you have 16 ones and 1 zero.
The reason why this question is slightly confusing, is if you didn't know the order to do the work you would add up all the 1's, and then multiply by zero. Obviously, anything multiplied by 0 is 0, but in this case you adding to that 0 once that operation is completed.
If you change the problem to (1+1+1+1...+1)*0, then you'd do the parenthesis first, and end up with 0 as your answer. GMATLA, thanks for your input. I rushed on this question and made the same mistake, but after careful analysis I later saw what made it slightly confusing. I really feel dumb for even getting this wrong, but hey I am learning something daily or having basic concepts reinforced to me.



Senior Manager
Joined: 01 Apr 2010
Posts: 298
Location: Kuwait
GPA: 3.2
WE: Information Technology (Consulting)

Re: Try this question on a friend posted to me on facebook [#permalink]
Show Tags
17 Apr 2012, 11:58
definately 15. Not as contraversial as 6÷2(1+2)= 1 or 9
Division should be before Multiplication but some suggest a paranthesis multiplication takes priority.



Director
Status: Can't wait for August!
Joined: 13 Sep 2011
Posts: 988
Location: United States (MA)
Concentration: Marketing, Strategy
GMAT 1: 660 Q44 V37 GMAT 2: 680 Q45 V38 GMAT 3: 710 Q45 V42
GPA: 3.32
WE: Information Technology (Retail)

Re: Try this question on a friend posted to me on facebook [#permalink]
Show Tags
26 Apr 2012, 11:43
GMATLA wrote: PEMDAS  Parenthesis, exponents, multiplication, division, addition, subtraction
This is what "order of operations" that you should do all math work in.
So first you'd do 1*0 = 0, then you'd add all the 1's together.
I see the answer as 15, but only because you have 16 ones and 1 zero.
The reason why this question is slightly confusing, is if you didn't know the order to do the work you would add up all the 1's, and then multiply by zero. Obviously, anything multiplied by 0 is 0, but in this case you adding to that 0 once that operation is completed.
If you change the problem to (1+1+1+1...+1)*0, then you'd do the parenthesis first, and end up with 0 as your answer. In the OP one of the 1s is a 1, making the answers 13 not 15. Someone posted this on FB a few weeks ago, with the caption "Why are so many people making a big deal out of this, its easy math, the answer is 0. Anything * 0 = 0" I didnt bother to respond, but it made my head hurt.



Director
Status: Can't wait for August!
Joined: 13 Sep 2011
Posts: 988
Location: United States (MA)
Concentration: Marketing, Strategy
GMAT 1: 660 Q44 V37 GMAT 2: 680 Q45 V38 GMAT 3: 710 Q45 V42
GPA: 3.32
WE: Information Technology (Retail)

Re: Try this question on a friend posted to me on facebook [#permalink]
Show Tags
26 Apr 2012, 11:46
aalba005 wrote: definately 15. Not as contraversial as 6÷2(1+2)= 1 or 9
Division should be before Multiplication but some suggest a paranthesis multiplication takes priority. I think the rule is anything inside a paranthesis comes first, and doesnt include anything outside. Writing 3*3 is the exact same thing as writing 3(3). Atleast that's always been my understanding



Intern
Joined: 15 Jan 2012
Posts: 9

Re: Try this question on a friend posted to me on facebook [#permalink]
Show Tags
26 Apr 2012, 20:32
It is 13.How to account as 0 .I am puzzled.




Re: Try this question on a friend posted to me on facebook
[#permalink]
26 Apr 2012, 20:32







