Question

in a two digit number, the digit in the ten's place is 3 more than the digit in the one's place. 7 times the sum of the digits is 3 more than the number. find the number

Answer 1

74 is the number    as  7 is 3 more than 4
7+4=11
11 x 7=77
so 74+3=77
hence the answer is 74

Answer 2

Let the two digit number be AB
A = B + 3
7(A + B) = 3 + AB
7(B + B + 3) = 3 + 10A + B(where AB can be written as 10A+B)
7(2B + 3) = 3 + 10(B + 3) +B
14B + 21 = 3 + 10B + 30 + B
14B + 21 = 11B + 33
14B - 11B = 33 - 21
3B = 12
B = 4
A = B + 3
A = 4 + 3 = 7
Therefore, the two digit number is 74.