Q. 195.0( 1 Vote )

A two - digit number is such that when it is multiplied by 9 then it will become double of number formed by interchanging the digits of the original number. If the difference of both the digits of the number is 7 then find the number.

Answer :

Let the digit in ten’s place be x and unit’s place be y

The difference between the two digit is 7

x - y = 7

x = y + 7 …equation (i)

When the digits are multiplied the resulting number is twice formed by interchanging the digits

2×(10x + y) = 9(10y + x)

20x + 2y = 90y + 9x

11x = 88y

x = 8y

Putting the value of x from equation (i) we get

y + 7 = 8y

7y = 7

y = 1

Putting the value in equation (i) we get

x = 8

So the two digit number is 18

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Goprep Genius Quiz on Linear Equations34 mins
Interactive session on Linear Equations in Two VariablesFREE Class
NCERT | Linear Equations41 mins
Quiz | Testing Your Skills on Linear Equation in Two Variables36 mins
Quiz | Important Questions on Linear Equations In Two Variables49 mins
Quiz | Imp. Qs. on Linear Equations44 mins
Champ Quiz | Do you Know about Linear Equations ?35 mins
Master Linear Equations40 mins
Champ Quiz | Linear Equation45 mins
Champ Quiz | Equations of Motion36 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses