Question

Certain two digit number is three times to the sum of their digits. If 45 added to this number the digits are interchanged

Answer 1

let no. = 10x+ y

digits= x and y

given,

10x+ y= 3(x+y)

10x+ y= 3x+3y

7x= 2y... thus, y= 7x/2...

10x+y+45= x+10y

9x+45= 9y. (divide by 9,)

thus, eqn. => x+5= y

substituting the value of y as 7x/2

we get...

7x/2= x+5

7x= 2x+10

5x= 10

x= 2...

y= 7....

thus, no. = 20+7= 27...

thus, y=