Question

I am a number under 10.My factors can add up to 13.What number am I?

Answer 1

Number 9 has factors 1, 3, 9 which add up to 1+3+9=13. It is easy to check that  the sum of factors for any other number under 10 is not equal to 13.

Число 9 имеет делители 1, 3, 9, сумма которых равна 1+3+9=13. Легко проверить, что сумма делителей для любого другого числа меньшего 10 не равна 13.

Answer 2

Identifying the Number

To find the number that is under 10 and whose factors add up to 13, we can start by listing the factors of each number under 10 and then checking which one satisfies the condition.

Let's start by listing the factors of each number under 10:

- For 1, the factors are 1. - For 2, the factors are 1 and 2. - For 3, the factors are 1 and 3. - For 4, the factors are 1, 2, and 4. - For 5, the factors are 1 and 5. - For 6, the factors are 1, 2, 3, and 6. - For 7, the factors are 1 and 7. - For 8, the factors are 1, 2, 4, and 8. - For 9, the factors are 1, 3, and 9.

Now, let's check which number's factors add up to 13.

- The factors of 6 (1, 2, 3, and 6) add up to 12, not 13. - The factors of 8 (1, 2, 4, and 8) add up to 15, not 13. - The factors of 9 (1, 3, and 9) add up to 13.

Therefore, the number that is under 10 and whose factors add up to 13 is 9.