## 5 digit number

We know that the fifth digit is half the fourth and a quarter of the third digit:

5th digit = a

The fourth digit is double the fifth:

4th digit = 2nd

The third digit is the quadruple of the fifth:

3rd digit = 4th

The third digit is half of the first and double of the fourth. We already know that:

3rd digit = 4th

4th digit = 2nd

So the first digit is double the third:

1st digit = 8a

The second digit is three times the fourth and has five units more than the fifth:

2nd digit = 3.2a = 6a

2nd digit = a + 5

Let's ride an equality. Knowing that a = 1, we can find the value of each digit:

1st digit = 8a = 8

2nd digit = 6a = 6

3rd digit = 4a = 4

4th digit = 2a = 2

5th digit = a = 1

The number sought is **86421**.

Back to the statement