Question

the sum of the digits of a two digit number is 9 the number is 6 times the unit digit find the number

Answer 1

Hi ,  Harsh    hope this will help you

Let the tens digit be x

so, the unit digit is =[9-x]  [because sum of the digits of a two digit number is 9]

so the nos is 10*x+ [9-x] ⇒10x+9-x ⇒9x-9

ATP

⇒9x+9 =6* [9-x]  [number is 6 times the unit digit]

⇒9x+9 =54-6x

⇒9x+6x =54-9

⇒15x=45

⇒x=45/15 ⇒3........  this is the nos of tens digit

⇒so, the unit digit is =[9-x] =9-3 ⇒6

∴the nos is 36

proof

the number is 6 times the unit digit [6] ==6*6 =36

The sum of the digits of a two digit number is 9 = ......[3+6]