Aptitude - Problems on Numbers - Discussion

Discussion Forum : Problems on Numbers - General Questions (Q.No. 3)

Problems on Numbers

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?

Cannot be determined

None of these

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 4 of 6.

Mayur said: 8 years ago

Thanks for the explanation.

Arpish said: 8 years ago

If in the question it is asked to find the 2 digit number, then how can we find it, can anyone explain?

Nikhilesh Israni said: 1 decade ago

Here we are writing the place value of each digit.

Suppose we have a number 7245, then the place value of 5 is 5*1=5 and the place value of 4 is 4*10=40. Similarly 2*100=200 and 7*1000=7000.

Hence if the number is 'xy' then y's place value is y*1=y and x's is x*10=10x. The same rule applies when we interchange the numbers.

Mahantesh said: 2 decades ago

(10x + y) - (10y + x) = 36

Venkat said: 2 decades ago

9x-9y=36
9(x-y)=36
x-y=4.

Priya P. said: 2 decades ago

Thanks.. Venkat

Bhupendra said: 1 decade ago

Why would we take 10 we can take 15 or other no also ?

Shu said: 1 decade ago

Why have they taken 10 only why not 9 or 4?

Punit Mandelia said: 1 decade ago

Actually it indicates the place, the order of place is hundred tens and unit place. So when we are talking about interchanging digit we are writing in place as we are interchanging there place. Got it.?

Jisha said: 1 decade ago

Please explain properly step by step.

Post your comments here:

Quick links

Quantitative Aptitude

Verbal (English)

Reasoning

Programming

Interview

Placement Papers

Aptitude - Problems on Numbers - Discussion

Current Affairs

Interview Questions

Group Discussions