Question

I need one each of the digits 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 and an extra 10 ones to write all the numbers from 10 to 20, Is Sofia right? How do you know? ​​

Answer 1

Sofia is correct; one each of the digits 0-9, plus an extra ten 1s, are needed to write all the numbers from 10 to 20 because the digit 1 appears eleven times while each other digit appears once.

Step-by-step explanation:

The question is asking whether Sofia is correct in saying she needs one each of the digits 0-9, plus an extra ten 1s, to write all the numbers from 10 to 20. Let's evaluate this claim step by step:

• The numbers from 10 to 20 are: 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.
• To write these numbers, we need the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 at least once.
• The digit 1 appears eleven times in total, as every number except 20 has a 1.
• Each of the other digits (0, 2, 3, 4, 5, 6, 7, 8, 9) appears only once.

Therefore, Sofia is correct. One each of the digits 0-9 and an extra ten 1s are indeed needed to write all the numbers from 10 to 20.

Answer 2

You only need one of each digit to write the numbers from 10 to 20 using the digits 0 to 9.

It seems there might be a misunderstanding in Sofia's request. If you need to write all the numbers from 10 to 20 using the digits 0 to 9, you only need one of each digit.

However, Sofia mentioned an extra 10 ones, which might be unnecessary.

To clarify, you can write the numbers from 10 to 20 using the digits 0 to 9 as follows: 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.

Each digit 0 to 9 is used at least once in these numbers.

There is no need for extra copies of the digit 1, or any other digit, to write this range of numbers.

Therefore, Sofia's request for an extra 10 ones is not correct for the specified task.