We know that the unit place is 3
So let’s consider the tens place as y
So the equation is (10y + 3)…………….. Equation (1)
From the question, seven times the sum of the digits is the number itself
∴from the above condition, 7(y + 3)……….. Equation (2)
Combining equation 1 and 2 we get,
7(y + 3) = (10y + 3)
7y + 21 = 10y + 3
7y -10y = 3 – 21
-3y = -18
∴ y = 6
Substituting the value of y in equation 1 we get,
10y + 3
10(6) + 3 = 60 + 3 = 63
∴ The required number is 63.
