Aptitude - Problems on Numbers - Discussion

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.

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.

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.

The given number is 36 which is +ve So the original number should be greater
Ex:
If ab is two-digit number b is in unit place and a is in 10th place (.etc..hundreds, tens, units)

Now the given ratio is 1:2 says that the ratio between 10s or 1s
The first number must greater than the reverse digit number.
So we give 2x in 10th place in the first number.
(Number)(10*2x+x)-(Reverse no-Small)(10x+2x)=36.
By solving X=4.

Then they said to find the sum and diff of number.
Ans=(2x+x)-(2x-x).
By solving;
We get the Ans is 8.

Thanks @Chinnadurai.

X is in units position and why is in ten's position. So the answer should be 16.

How come 10 here? Please explain.

I am not understanding it, please someone explain me.

I am not getting this, please anyone explain me in detail.

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.