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 4 of 4.
Sudeshna said:
1 decade ago
If we take the tens digit as 10x then also we will get the value of 10x = 9 and y = 6
So we can easily write the answer as 96 as 9-6 gives 3 and 6-9 gives -3!
So the answer can be determined.
So we can easily write the answer as 96 as 9-6 gives 3 and 6-9 gives -3!
So the answer can be determined.
Balu said:
1 decade ago
Please why we not take tens digit as 10x and unit digit as y. Please explain as it taken in previous question.
Ajay said:
1 decade ago
Please explain why we are not taking the tens digit as 10x and the ones digit as y, Like it was done in the previous questions?
S Vishnu Vardhan said:
1 decade ago
Could somebody explain why we are not taking the tens digit as 10x and the ones digit as y, Like it was done in the previous questions?
Mehran said:
1 decade ago
Assumed Number = XY.
X-Y = 15----- (i)
X+Y = 3 ------ (ii)
By solving (i)&(ii) we reach at;
X = 9 & Y = 6.
So, Assumed Number is 96,
Which satisfy both equations (i) & (ii).
If we take 69 that is not appropriate because in Equation (ii).
It comes with negative value of -3.
So, correct and answer is 96 that is determined here.
X-Y = 15----- (i)
X+Y = 3 ------ (ii)
By solving (i)&(ii) we reach at;
X = 9 & Y = 6.
So, Assumed Number is 96,
Which satisfy both equations (i) & (ii).
If we take 69 that is not appropriate because in Equation (ii).
It comes with negative value of -3.
So, correct and answer is 96 that is determined here.
Sally said:
1 decade ago
Could somebody explain why we are not taking the tens digit as 10x and the ones digit as y, Like it was done in the previous questions?
Moola V reddy said:
1 decade ago
I agree with Dominic
always read the question carefully
1.sum of the two digits
2.difference between them
sundar said good example of difference
but there is no sum
always read the question carefully
1.sum of the two digits
2.difference between them
sundar said good example of difference
but there is no sum
Ramesh said:
1 decade ago
I agree with Sundar.
Sundar said:
1 decade ago
@Dominic
You are wrong. The given answer is correct.
I want to ask a question to you.
Assume your height is 165 cm and your friend's height is 170 cm.
Now tell me what is the height-difference between you and your friend?
Is it 5 cm or -5cm ?
We usually write difference between x and y as
X ~ Y NOT as X - Y.
Hence the given answer 'Cannot be determined' is correct.
You are wrong. The given answer is correct.
I want to ask a question to you.
Assume your height is 165 cm and your friend's height is 170 cm.
Now tell me what is the height-difference between you and your friend?
Is it 5 cm or -5cm ?
We usually write difference between x and y as
X ~ Y NOT as X - Y.
Hence the given answer 'Cannot be determined' is correct.
Dominic said:
1 decade ago
If we take 69 as answer.
Sum becomes:6+9=15.
But difference become: 6-9=-3.
But from the question, the sum should be 15 and the difference 3, not -3. On this note, I strongly believe that, the correct answer is 96, because.
Sum: 9+6=15,
And difference: 9-6=3.
Sum becomes:6+9=15.
But difference become: 6-9=-3.
But from the question, the sum should be 15 and the difference 3, not -3. On this note, I strongly believe that, the correct answer is 96, because.
Sum: 9+6=15,
And difference: 9-6=3.
(1)
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers