No products in the cart.

The sum of the digits of …

CBSE, JEE, NEET, CUET

CBSE, JEE, NEET, CUET

Question Bank, Mock Tests, Exam Papers

NCERT Solutions, Sample Papers, Notes, Videos

The sum of the digits of a two digit number is 9.Also, nine times this number is twice the number obtained by reversing the order of the digits. Find the number.
  • 1 answers

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.

https://examin8.com Test

Related Questions

Find the nature of quadratic equation x^2 +x -5 =0
  • 0 answers
Venu Gopal has twice
  • 0 answers
sin60° cos 30°+ cos60° sin 30°
  • 2 answers
Prove that root 8 is an irration number
  • 2 answers
(A + B )²
  • 1 answers
X-y=5
  • 1 answers

myCBSEguide App

myCBSEguide

Trusted by 1 Crore+ Students

Test Generator

Test Generator

Create papers online. It's FREE.

CUET Mock Tests

CUET Mock Tests

75,000+ questions to practice only on myCBSEguide app

Download myCBSEguide App