Question

In a 3-digit number, the middle digit is 3 times the last digit and 4 more than the first digit. All the digits are odd and can only be used once. What is the 1st number?

Answer 1

5

Explanation:

This is quite some trial and error question.

Based on the question, the numbers we can use are 1,3,5,7 and 9.

We will start with the middle digit first.

Since the question has stated it is 3 times the last digit, the number has to be in multiples of 3.

So we are left with: 3 and 9.

Then, the question also states the middle digit is 4 more than the first digit. See, its a digit, so the value cannot be less than 1 (odd numbers only and no negative values), so if we subtract 4 to the middle digit to find the first, it should still be a Positive Single numerical value.

3 - 4 = -1

9 - 4 = 5

Therefore, this middle digit is = 9.

Since we know the middle digit = 9

The first digit will be 9 - 4 = 5

The whole value is now 593.