If you wrote down all the numbers from 1 - 100, how many times you write 3?

Options

A. 18
B. 11
C. 20
D. 21

Explanation

To find out how many times the digit '3' appears when writing down all the numbers from 1 to 100, we can break it down into two parts: the occurrences of '3' in the tens place and the occurrences of '3' in the units place.

### Step 1: Count occurrences of '3' in the units place
We will look at the numbers from 1 to 100 and check the units place for the digit '3'.

- The numbers that have '3' in the units place are:
- 3, 13, 23, 33, 43, 53, 63, 73, 83, 93

There are 10 occurrences of '3' in the units place.

### Step 2: Count occurrences of '3' in the tens place
Next, we will check the tens place for the digit '3'.

- The numbers that have '3' in the tens place are:
- 30, 31, 32, 33, 34, 35, 36, 37, 38, 39

There are 10 occurrences of '3' in the tens place.

### Step 3: Add the occurrences from both places
Now, we add the occurrences from the units place and the tens place together.

- Total occurrences of '3' = Occurrences in units place + Occurrences in tens place
- Total occurrences of '3' = 10 (units) + 10 (tens) = 20

### Final Answer
Therefore, the digit '3' is written a total of **20 times** when writing all the numbers from 1 to 100.

---