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 3 of 5.
Abi said:
8 years ago
Where is the 9 from? Please explain.
Sakshi said:
8 years ago
Thanks for the explanation @KCS.
Aaff said:
7 years ago
Thank you for the answer @Anusha.
Harshit said:
7 years ago
Correct answer should be 16. Ten's digit is X and Unit digit is 2X as the ratio given is 1:2 and not 2:1.
Vamsikrishnareddy said:
7 years ago
I am not getting this, please anyone explain me in detail.
Chitta meher said:
6 years ago
How come 10 here? Please explain.
Karthik said:
6 years ago
X is in units position and why is in ten's position. So the answer should be 16.
Leopard said:
1 decade ago
Let's the digits are x & y.
The ratio between them is x:y = 1:2.
So y=2x.
Hence y is ten digit no.
According to statement,
(10y+x)-(10x+y) = 36.
(10*2x+x)-(10x+2x) = 36.
21x-12x = 36.
9x = 36.
x = 4..
(y+x)-(y-x) = (2x+4)-(2x-4).
= (8+4)-(8-4).
= 12-4 = 8.
The ratio between them is x:y = 1:2.
So y=2x.
Hence y is ten digit no.
According to statement,
(10y+x)-(10x+y) = 36.
(10*2x+x)-(10x+2x) = 36.
21x-12x = 36.
9x = 36.
x = 4..
(y+x)-(y-x) = (2x+4)-(2x-4).
= (8+4)-(8-4).
= 12-4 = 8.
Pavithra said:
2 decades ago
I get the answer as 16.
Diff in digits: (x+y)-(x-y)
=2y
=2(2x)
=4x.
Finding the value of x we get, x=4;
So ans = 4(4) = 16.
Diff in digits: (x+y)-(x-y)
=2y
=2(2x)
=4x.
Finding the value of x we get, x=4;
So ans = 4(4) = 16.
Santosh said:
2 decades ago
Why we have to take 2x in units place rather than x ? can any one explain.
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