Question

The units digit of a two-digit number is 3 and seven times the sum of digits is the number itself. Find the number.

Answer 1

Let's assume that the number be 10a+b

Now according to the question
b=3 and
7(a+b) = 10a+b
7a+21=10a+3
3a=18
a=6

So, the number is 63

Answer 2

Step-by-step explanation:

Unit of two digit number is 3

Let the tens digit number be x

The Number will be 10x + 3

Sum of two digit number = x + 3

According to the question now :

7(x + 3) = 10x + 3

7x + 21 = 10x + 3

21 - 3 = 10x - 7x

18 = 3x

x = 18/3

x = 6

Therefore, the tens digit number is 6.

Hence,

The required number = 10x + 3 = 10(6) + 3 = 63.