Question

13. The difference between two numbers is 26 and one number is three times the other.
14. 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​

Answer 1

 

13.

• let the number be x

• second number 3x
• 3x-x = 26

• 2x=26
• x=26/2
• x=13

14.

• Let the unit digit and tens digits of the number be x and y                    
• Number = 10y + x                    
• Number after reversing the digits = 10x + y    
• ⇒  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.