Correct Answer - Option 1 : 23
Let, the unit place digit be: "x".
Let, the tens place digit be: "y".
Therefore, the number will be:
10y + x.
According to the question, this two-digit number is thrice the sum of digits.
→ 3(x + y) = 10y + x.
→ 3x + 3y = 10y + x.
→ 2x = 7y.
→ x = (7/2)y ----(1).
Now, 45 will be added if the digits are reversed.
→ 10y + x + 45 = 10x + y.
→ 9y + 45 = 9x.
Putting the value of "x" from the equation (1)
→ 9y + 45 = 9(7/2)y.
→ 18y + 90 = 63y.
→ 90 = 45y.
→ y = 90/45.
→ y = 2.
Putting the value of "y" in equation (1).
→ x = (7/2) × 2.
→ x = 7.
As the tense digit is 2 and one digit is 7.
Therefore, the number is "27".
Therefore, the correct answer should be "Option3: 27".
