Aptitude - Problems on Numbers - Discussion
Discussion Forum : Problems on Numbers - General Questions (Q.No. 6)
6.
The sum of the digits of a two-digit number is 15 and the difference between the digits is 3. What is the two-digit number?
Answer: Option
Explanation:
Let the ten's digit be x and unit's digit be y.
Then, x + y = 15 and x - y = 3 or y - x = 3.
Solving x + y = 15 and x - y = 3, we get: x = 9, y = 6.
Solving x + y = 15 and y - x = 3, we get: x = 6, y = 9.
So, the number is either 96 or 69.
Hence, the number cannot be determined.
Discussion:
41 comments Page 2 of 5.
Kaveri Malavath said:
6 years ago
If he specified the difference between the first digit and the second digit is 3., then we can determine the answer, which is 96. Since he did not mention anything we can't determine the number.
Snehal said:
6 years ago
What is correct answer?
Anaga said:
7 years ago
(a+b)=(b+a).
(a-b)!=(b-a).
solution:
a+b=15
a-b=3
______
a=9,b=6 i.e ab=96.
b+a=15
b-a=3
______
b=9,a=6 i.e ab=69.
As both the options are correct and present in the solution we cannot determine the correct answer.
(a-b)!=(b-a).
solution:
a+b=15
a-b=3
______
a=9,b=6 i.e ab=96.
b+a=15
b-a=3
______
b=9,a=6 i.e ab=69.
As both the options are correct and present in the solution we cannot determine the correct answer.
Joe said:
8 years ago
Yes, 96 is the correct Answer.
Manikandan said:
8 years ago
I don't agree with this solution this is because if we take the number as 69 then,
6+9=15 which is said to be as correct but on the other case 6-9=-3 but in the question it is given the resultant as 3. Therefore the correct solution for this will be 96.
6+9=15 which is said to be as correct but on the other case 6-9=-3 but in the question it is given the resultant as 3. Therefore the correct solution for this will be 96.
Vijay said:
8 years ago
We use 10x only if we want to represent the whole number. For example, if x=9, y=4, we cannot write x+y because the answer will be 13, but we must write 10x+y = 90+4 =94.
But here we are referring to only the digit in ten's place which is 9 for example.
But here we are referring to only the digit in ten's place which is 9 for example.
Vicky said:
8 years ago
I agree @Dominic.
96 is the correct answer.
96 is the correct answer.
ROCKY said:
9 years ago
We can't take (10x+y) and (10x-y). Because the question is given that the sum of the digits of a two - digit number.
Exam: a two digit number=98, then sum of the digits 9 and 8=9+8, difference of the digits 9 and 8=9-8.
Exam: a two digit number=98, then sum of the digits 9 and 8=9+8, difference of the digits 9 and 8=9-8.
Naina said:
9 years ago
Hi,
Can anyone explain, why we didn't take (10x+y) and (10x-y)?
Can anyone explain, why we didn't take (10x+y) and (10x-y)?
Pooja P Kumar said:
9 years ago
I Strongly agree @Sundar. That's absolutely correct.
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