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:
40 comments Page 2 of 4.
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:
7 years ago
Yes, 96 is the correct Answer.
Manikandan said:
7 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:
7 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:
8 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:
8 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:
8 years ago
I Strongly agree @Sundar. That's absolutely correct.
Maggie said:
8 years ago
Answer should be 96.
Since 6-9=-3 and 9-6=3.
Since 6-9=-3 and 9-6=3.
Dipak said:
9 years ago
Agree @Jagdish.
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