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What is the value of a positive integer x? (1) x is three times the
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10 Dec 2018, 02:32
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31% (02:34) correct 69% (02:01) wrong based on 177 sessions
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What is the value of a positive integer x? (1) x is three times the sum of its digits (2) x is a twodigit number
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Re: What is the value of a positive integer x? (1) x is three times the
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11 Dec 2018, 02:29
Bunuel wrote: What is the value of a positive integer x?
(1) x is three times the sum of its digits (2) x is a twodigit number GMATinsight : Sir could you please review my solution and check where am I going wrong, correct answer given is A .. I am not sure why so.. we need to find the value of +ve integer X stmnt 1: X = 3* ( sum of its digits) its not clear how many digit number it is , if its 1 digit no then X= 3 .A if its a 2 digit no then X= 3*(10A+B) .. so on so value of X would vary as we are not sure of the value of 2 digits it can be (11,12 .. so on ) so x can be X= 3(2); 6 or 3(3); 9 or else it can be a 3 digit no as well eg 111 ; 3* (3); 9 100 : 3(1); 3 in sufficient Stmnt 2: X is a two digit no.. again value of 2 digit not clear so X cannot be determined , in sufficient From 1 & 2: x is a 2 digit no and it is 3 times the sum of the digits ; this would be again in sufficient as we would get many values of X as 2 digit no can be many IMO E should be answer..



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Re: What is the value of a positive integer x? (1) x is three times the
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11 Dec 2018, 03:06
Answer is A. From stmnt 1,we know X=3*( sum of digits of X) Now,supposing X is A3 digit no.,999,sum of digits =27,and 3 times 27= 81,a 2 digit no.which is contradictory in itself. Considering X=100,sum of digits=1,hence 3 times 1=1,a one digit no. This means X should be a 2 digit no. Let X=10a+b Then 10a+b= 3*(a+b) Or 7a=2b,or a=3.5b. Now,for the 2 digit no.X,a and b should both be integers,and should be 0<a,b<=9. Only digits satisfying this are 2 and 7. So,X=27= 3*(2+7) Sufficient.
Stmnt 2 is insufficient
So,A
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Re: What is the value of a positive integer x? (1) x is three times the
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11 Dec 2018, 03:19
anshkool4u wrote: Answer is A. From stmnt 1,we know X=3*( sum of digits of X) Now,supposing X is A3 digit no.,999,sum of digits =27,and 3 times 27= 81,a 2 digit no.which is contradictory in itself. Considering X=100,sum of digits=1,hence 3 times 1=1,a one digit no. This means X should be a 2 digit no. Let X=10a+b Then 10a+b= 3*(a+b) Or 7a=2b,or a=3.5b. Now,for the 2 digit no.X,a and b should both be integers,and should be 0<a,b<=9. Only digits satisfying this are 2 and 7. So,X=27= 3*(2+7) Sufficient.
Stmnt 2 is insufficient
So,A
Posted from my mobile device anshkool4uquoting your line : Let X=10a+b Then 10a+b= 3*(a+b) Or 7a=2b,or a=3.5b.this would be 3.5a=b Now,for the 2 digit no.X ,a and b should both be integers,and should be 0<a,b<=9. " how did you come up to this range"? agree that a and b have to be between 09 but why specifically you have mentioned that "be 0<a,b<=9."



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Re: What is the value of a positive integer x? (1) x is three times the
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24 Dec 2018, 00:42
Let X be of form pq . So basically X =10P + Q
A> 3x = P + Q > 2Q = 7P For this to hold P should be 2 and Q should be 7 27 is the unique no. Sufficient
B> No unique value. Insufficient
Answer A
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Re: What is the value of a positive integer x? (1) x is three times the
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24 Dec 2018, 01:17
Bunuel wrote: What is the value of a positive integer x?
(1) x is three times the sum of its digits (2) x is a twodigit number Par of GMAT CLUB'S New Year's Quantitative Challenge Set
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What is the value of a positive integer x? (1) x is three times the
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07 Jan 2019, 10:13
Archit3110 wrote: anshkool4u wrote: Answer is A. From stmnt 1,we know X=3*( sum of digits of X) Now,supposing X is A3 digit no.,999,sum of digits =27,and 3 times 27= 81,a 2 digit no.which is contradictory in itself. Considering X=100,sum of digits=1,hence 3 times 1=1,a one digit no. This means X should be a 2 digit no. Let X=10a+b Then 10a+b= 3*(a+b) Or 7a=2b,or a=3.5b. Now,for the 2 digit no.X,a and b should both be integers,and should be 0<a,b<=9. Only digits satisfying this are 2 and 7. So,X=27= 3*(2+7) Sufficient.
Stmnt 2 is insufficient
So,A
Posted from my mobile device anshkool4uquoting your line : Let X=10a+b Then 10a+b= 3*(a+b) Or 7a=2b,or a=3.5b.this would be 3.5a=b Now,for the 2 digit no.X ,a and b should both be integers,and should be 0<a,b<=9. " how did you come up to this range"? agree that a and b have to be between 09 but why specifically you have mentioned that "be 0<a,b<=9." Hi Archit, the range quoted is because if a=0, then the no. ab would just become a single digit no. and since 3.5a=b, value of b cannot be 0 because a cannot be 0. I hope that makes it clear.



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Re: What is the value of a positive integer x? (1) x is three times the
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25 Oct 2019, 07:22
Bunuel wrote: What is the value of a positive integer x?
(1) x is three times the sum of its digits (2) x is a twodigit number (2) x is a twodigit number insufic.(1) x is three times the sum of its digits sufic.digits: {0,1,2,3,4,5,6,7,9} if x = onedigit number: A, then A=3A is only possible if A=0, but x≥1; out. if x = threedigit number: then 100 ≤ x ≤ 999, but the max possible sum of digits = {9,9,9} = 27; out. if x = twodigit number: 10A+B, then 10A+B=3(A+B)… 7A=2B…A=2B/7=integer; since 1≤A≤9, 0≤B≤9 and A=2B/7=integer… B has multiple of 7: B=(0,7); B=0; A=2B/7…A=0…but A≥1; out; B=7; A=2B/7…A=2…so, x=27 Answer (A)




Re: What is the value of a positive integer x? (1) x is three times the
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