Aptitude - Problems on Numbers - Discussion
Discussion Forum : Problems on Numbers - General Questions (Q.No. 3)
3.
The difference between a two-digit number and the number obtained by interchanging the positions of its digits is 36. What is the difference between the two digits of that number?
Answer: Option
Explanation:
Let the ten's digit be x and unit's digit be y.
Then, (10x + y) - (10y + x) = 36
9(x - y) = 36
x - y = 4.
Video Explanation: https://youtu.be/7QOJjAmGVx0
Discussion:
59 comments Page 2 of 6.
Tanya said:
8 years ago
(10x + y) - (10y + x) = 36.
Will someone explain to me why we equalize it with 36?
Is it because it is stated, "the number obtained by interchanging the positions of its digits is 36".
Then please explain me the question " What is the difference between the two digits of that number"?
Will someone explain to me why we equalize it with 36?
Is it because it is stated, "the number obtained by interchanging the positions of its digits is 36".
Then please explain me the question " What is the difference between the two digits of that number"?
(1)
Anshu said:
1 decade ago
Let x and y be two digits of the Numbers.
Such that x is in tens position and y is at the ones place
So xy is the number
xy = 10(x) + y(1) ----------> (1)
On interchanging the digits we get
yx = y(10) + x(1) ----------> (2)
(10x + y) - (10y + x)= 36
10x + y - 10y - x = 36
9x - 9y = 36
x - y = 4
Such that x is in tens position and y is at the ones place
So xy is the number
xy = 10(x) + y(1) ----------> (1)
On interchanging the digits we get
yx = y(10) + x(1) ----------> (2)
(10x + y) - (10y + x)= 36
10x + y - 10y - x = 36
9x - 9y = 36
x - y = 4
(1)
Aakash said:
7 years ago
Say 1 no is 84.
Then interchanging it we will get 48.
Difference between these two number is 36.
So, the difference between the two digit will be 4.
Then interchanging it we will get 48.
Difference between these two number is 36.
So, the difference between the two digit will be 4.
(1)
Ayushi Nandy said:
4 years ago
Thanks everyone for explaining the answer.
(1)
Abhijit Kale said:
10 years ago
Guys I agree to your explanation but I found a No. 73. If we reverse it we'll get a no 37. And difference between these two nos is 36.
And difference between digits of this no is 3. All these things matches the criteria of this question except my answer. Please rectify me if I am wrong.
And difference between digits of this no is 3. All these things matches the criteria of this question except my answer. Please rectify me if I am wrong.
Abhijit Kale said:
10 years ago
Guys I agree to this explanation but I found a no which matches the criteria of this question. no is 73. If we reverse is we will get 37.
And difference between 73 and 37 is 36. And difference between digits is 3. Am I wrong?
And difference between 73 and 37 is 36. And difference between digits is 3. Am I wrong?
Nagma jabee said:
10 years ago
Thanks @Nikhilesh and Isran.
Qasim said:
10 years ago
Why do we interchanging the number?
Balaji said:
10 years ago
@Abhijit.
The number your are interchanging is 73 so you have you have to see the difference between 7 and 3 which is equal to 4. And you can check this with the number 84 & 95.
The number your are interchanging is 73 so you have you have to see the difference between 7 and 3 which is equal to 4. And you can check this with the number 84 & 95.
Bgnr said:
9 years ago
Why we take x and why in addition to 10x and 10y, can anyone explain?
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