In a three-digit number, the hundred’s and ten’s digit are the same. The unit’s digit is 3 more than the hundred’s digit. If the number is reversed, the new number is 72 more than twice the original number. How do you find the number?

1 Answer
Apr 18, 2016

So you can write the number as aab where b=a+3

Explanation:

This means that the value of the original number is:
=100a+10a+(a+3)=111a+3

The reversed number will be baa, or:
=100(a+3)+10a+a=111a+300

Twice the original number plus 72 equals the new number:
2(111a+3)+72=111a+300->
222a+78=111a+300->

Subtract 111a and 78 from both sides:
111a=222->a=2->b=a+3=5->

The original number is 225

Check your answer:
2xx225+72=522, check!