I am a 3-digit number. My hundred’s digit is 3 less than my ten’s digit. My ten’s digit is 3 less than my unit’s digit. The sum of all three digits is 15. Who am I?

Question

Bright Tutorials · Accepted Answer

Let the ten’s place digit be x.
Then hundred’s place digit = x – 3
Unit’s digit = x + 3
Sum of digits = 15
According to the question,
(x – 3) + x + (x + 3) = 15
⇒ 3x = 15
Divide both sides by 3
$\frac{3 x}{3}=\frac{15}{3}$
⇒ x = 5
Ten’s digit = 5
Hundred’s digit = 5 – 3 = 2
Unit’s digit = 5 + 3 = 8
Number formed = 258

Finding the Unknown — Question 3