Question

the unit digit of a 2 digit no. is 3 and 7 times the sum of the digits is the no. itself.Find the number.

Answer 1

let u=units digit=3

let t=tens digit

10t+u=number

..

7(u+t)=10t+u

7u+7t=10t+u

21+7t=10t+3

3t=18

t=6

10t+u=60+3=63

number=63