The sum of the digits of …

CBSE, JEE, NEET, CUET
Question Bank, Mock Tests, Exam Papers
NCERT Solutions, Sample Papers, Notes, Videos
Related Questions
Posted by Parinith Gowda Ms 2 months, 2 weeks ago
- 0 answers
Posted by Vanshika Bhatnagar 1 year, 3 months ago
- 2 answers
Posted by Parinith Gowda Ms 2 months, 2 weeks ago
- 1 answers
Posted by Sahil Sahil 1 year, 3 months ago
- 2 answers
Posted by Hari Anand 5 months, 1 week ago
- 0 answers
Posted by Kanika . 5 days, 14 hours ago
- 1 answers

myCBSEguide
Trusted by 1 Crore+ Students

Test Generator
Create papers online. It's FREE.

CUET Mock Tests
75,000+ questions to practice only on myCBSEguide app
myCBSEguide
Yogita Ingle 5 years, 3 months ago
The sum of digits f a two digit number is 9.
Also nine times this number is twice the number obtained by reversing the order of digit.
Let the unit digit and tens digits of the number be x and y
Number = 10y + x
Number after reversing the digits = 10x + y
According to the question,
⇒ x + y = 9 ... (i)
⇒ 9(10y + x) = 2(10x + y)
⇒ 88y - 11x = 0
⇒ -x + 8y =0 ... (ii)
Adding equation (i) and (ii), we get
⇒ 9y = 9
⇒ y = 1 ... (iii)
Putting the value in equation (i), we get
⇒ x = 8
Hence, the number is 10y + x = 10 × 1 + 8 = 18.
1Thank You