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:
45 comments Page 5 of 5.
Bhargavi said:
4 years ago
From 3rd question,we can say x-y=4.
We have to find diff of ( sum of digits n diff of digits).
(X+y)-(x-y)=0.
X+y=4.
From 2 equations,we get X=4, sub X value then y=0,
So 2 numbers are 40 and 04,
Sum is 44,diff is 36.
So, diff is 44 - 36 = 8.
We have to find diff of ( sum of digits n diff of digits).
(X+y)-(x-y)=0.
X+y=4.
From 2 equations,we get X=4, sub X value then y=0,
So 2 numbers are 40 and 04,
Sum is 44,diff is 36.
So, diff is 44 - 36 = 8.
(9)
Maganizo Chithila said:
4 years ago
Ratio is 1:2
we will consider 1 and 2 as the numbers.
And have variable x after the subtracting.
then (21 -12)x=36.
Then 9x=36
And x=4 .
And have 2x for the second number which is 8.
the difference is 8-4 = 4.
the sum of 8+4 = 12.
Therefore the difference is 12-4 = 8.
we will consider 1 and 2 as the numbers.
And have variable x after the subtracting.
then (21 -12)x=36.
Then 9x=36
And x=4 .
And have 2x for the second number which is 8.
the difference is 8-4 = 4.
the sum of 8+4 = 12.
Therefore the difference is 12-4 = 8.
(16)
Swamy said:
2 years ago
Let's assume 2 digit number is 10.
10x - 01x = 36,
9x = 36,
x = 4.
Coming to question; 1:2;
1x:2x.
1x4: 2x4.
4:8.
Then the answer is 8.
10x - 01x = 36,
9x = 36,
x = 4.
Coming to question; 1:2;
1x:2x.
1x4: 2x4.
4:8.
Then the answer is 8.
(35)
KHY said:
2 years ago
So after devoting 30 min, finally I got this! Hopes this will help you all.
Let's take a two-digit no. = XY( 10x +y)
Imp =suppose 27=2 @tenth +7 @unit)
Ist condition:
Ratio is 1:2
Let's assume x = a.
Y= 2a.
10x+y = 10 *a +2a = 10a + 2a = 12a --->(1)
10y+x = 10 * 2a +a =20a + a = 21a ---> (2).
Difference between.
21a - 12a = 36,
9a = 36,
a = 4.
So,
Fill the value in (1,(2).
I.e. 12a =12*4 = 48
21a = 21*4 = 84.
Sum of digits=4 +8 = 12.
Difference = 8-4 = 4.
Differ. between sum and subtraction,
12-4 = 8.
Hope, I am able to explain you simply as possible.
Let's take a two-digit no. = XY( 10x +y)
Imp =suppose 27=2 @tenth +7 @unit)
Ist condition:
Ratio is 1:2
Let's assume x = a.
Y= 2a.
10x+y = 10 *a +2a = 10a + 2a = 12a --->(1)
10y+x = 10 * 2a +a =20a + a = 21a ---> (2).
Difference between.
21a - 12a = 36,
9a = 36,
a = 4.
So,
Fill the value in (1,(2).
I.e. 12a =12*4 = 48
21a = 21*4 = 84.
Sum of digits=4 +8 = 12.
Difference = 8-4 = 4.
Differ. between sum and subtraction,
12-4 = 8.
Hope, I am able to explain you simply as possible.
(77)
Sirjan said:
2 years ago
As ratio of the numbers is 1:2 and it's 2 digit number so possible numbers are only - 12, 24, 36 and 48.
Among those 48 and 84 (reversed 48) gives difference of 36.
So, the digit is 48.
The sum of digits, 8 + 4 = 12
Difference of digits, 8 - 4 = 4
Required difference. 12 - 4 = 8.
Among those 48 and 84 (reversed 48) gives difference of 36.
So, the digit is 48.
The sum of digits, 8 + 4 = 12
Difference of digits, 8 - 4 = 4
Required difference. 12 - 4 = 8.
(41)
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