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.
Anoj said:
7 years ago
How can it solve using only one variable?
(1)
Aakash said:
8 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)
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)
Shams said:
1 decade ago
Hi,
There is not taking 10 digit number. that is the 10th place of number we are finding. see
There are 2 two digit is let x and y,
So the number will be 10x+y (x is at tenth position & y is at unit position)
Because for example number 85.
x=8 and y=5.
So, 10x+y = ( 10 * 8 + 5 = 85 ).
Not do the number (xy = 8*5 = 40) or (10xy = 10*8*5 =400 ).
Now for answer proceed further according to question.
I think its help to you.
There is not taking 10 digit number. that is the 10th place of number we are finding. see
There are 2 two digit is let x and y,
So the number will be 10x+y (x is at tenth position & y is at unit position)
Because for example number 85.
x=8 and y=5.
So, 10x+y = ( 10 * 8 + 5 = 85 ).
Not do the number (xy = 8*5 = 40) or (10xy = 10*8*5 =400 ).
Now for answer proceed further according to question.
I think its help to you.
(1)
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)
Banasree Debbarma said:
10 years ago
How does 10x, y, 36 come?
Abhijit Kale said:
1 decade 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?
Bgnr said:
10 years ago
Why we take x and why in addition to 10x and 10y, can anyone explain?
Balaji said:
1 decade 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.
Qasim said:
1 decade ago
Why do we interchanging the number?
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