Aptitude - Problems on Numbers - Discussion
Discussion Forum : Problems on Numbers - General Questions (Q.No. 4)
4.
The difference between a two-digit number and the number obtained by interchanging the digits is 36. What is the difference between the sum and the difference of the digits of the number if the ratio between the digits of the number is 1 : 2 ?
Answer: Option
Explanation:
Since the number is greater than the number obtained on reversing the digits, so the ten's digit is greater than the unit's digit.
Let ten's and unit's digits be 2x and x respectively.
Then, (10 x 2x + x) - (10x + 2x) = 36
9x = 36
x = 4.
Required difference = (2x + x) - (2x - x) = 2x = 8.
Discussion:
46 comments Page 2 of 5.
Nathi said:
2 decades ago
At first we should decide the digits of 10's & unit's be X & 2X respectively.
((10 x 2X) + X) - ((10 x X) + 2X) = 36
(20X + X) - (10X + 2X) = 36
21X - 12X = 36
9X = 36
X = 4
The difference between two digits = (2X+X)-(2X-x)
= 3X - X
= 2X
= 2(4)
= 8
((10 x 2X) + X) - ((10 x X) + 2X) = 36
(20X + X) - (10X + 2X) = 36
21X - 12X = 36
9X = 36
X = 4
The difference between two digits = (2X+X)-(2X-x)
= 3X - X
= 2X
= 2(4)
= 8
(2)
Pooja said:
1 decade ago
Hello Friends,
Suppose x & y two digits and the ratio b/w the digits of the number is 1:2
Therefor, x:y = 1:2
So, y = 2x ..........equation 1.
Hence, y is in ten's position and x is in unit place.
According to the question,
(10y + x) - (10x + y) = 36
From equation 1, we get y = 2x
(10*2x + x ) - (10x + 2x) = 36
(20x + x) - (12x) = 36
21x - 12x = 36
9x = 36
x = 4 ........... equation 2.
Now putting the value of x in equation 1.
y = 2*4
y = 8
Sum and the difference of the digits of the number (x + y) & (x - y) respectively.
According to question,
Difference between (x + y) & (x - y).
= (y+ x) - (y - x) ............. equation 3.
Putting the value of x = 4 & y = 8 in the above equation.
We get,
= (8 + 4) - (8 - 4).
= 12 - 4.
= 8.
Suppose x & y two digits and the ratio b/w the digits of the number is 1:2
Therefor, x:y = 1:2
So, y = 2x ..........equation 1.
Hence, y is in ten's position and x is in unit place.
According to the question,
(10y + x) - (10x + y) = 36
From equation 1, we get y = 2x
(10*2x + x ) - (10x + 2x) = 36
(20x + x) - (12x) = 36
21x - 12x = 36
9x = 36
x = 4 ........... equation 2.
Now putting the value of x in equation 1.
y = 2*4
y = 8
Sum and the difference of the digits of the number (x + y) & (x - y) respectively.
According to question,
Difference between (x + y) & (x - y).
= (y+ x) - (y - x) ............. equation 3.
Putting the value of x = 4 & y = 8 in the above equation.
We get,
= (8 + 4) - (8 - 4).
= 12 - 4.
= 8.
(2)
Sikha said:
2 decades ago
It can't b (x+y) - (x-y).
Rather it could be (10x +y) - (10y + x).
Rather it could be (10x +y) - (10y + x).
(1)
Sravanthi said:
2 decades ago
Hi I can't understand this problem. Any more explnation please.
(1)
Md Parvez Islam said:
6 years ago
Thanks @Chinnadurai.
(1)
Jonsihay said:
1 decade ago
The Problem should be re-stated specially on the aspect of the ratio.
It should "NOT JUST BE" 'if the ratio between the digits of the number is 1:2. But it should be restated as 'if the ratio between the unit's and ten's digits of the number is 1:2.
Then if that's ok, I think reliably be solvable!
It should "NOT JUST BE" 'if the ratio between the digits of the number is 1:2. But it should be restated as 'if the ratio between the unit's and ten's digits of the number is 1:2.
Then if that's ok, I think reliably be solvable!
(1)
Kolkata said:
7 years ago
I am not understanding it, please someone explain me.
(1)
Ramya said:
2 decades ago
Hi I could not understand this problem. Can anyone explain this more clearly please?
(1)
Karthik said:
6 years ago
X is in units position and why is in ten's position. So the answer should be 16.
Sarita said:
8 years ago
Thank you for the answer @Anju.
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