Question

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

Answer 1

let the no. is 10x +y
ATQ
x+y=9. ...1
and 6y=10x+y
10x-5y=0
2x-y=0. ...2
from 1 & 2
x=3 & y=6
so the no. =10x+y=10×3 +6=36