What will come in place of question mark (?) .
0.121 + 0.00121 + 0.000121 = ?

Options

A. 0.122331
B. 0.363
C. 0.00363
D. 0.212331

Answer

To solve the equation \(0.121 + 0.00121 + 0.000121\), we will follow these steps:

### Step 1: Align the decimal points
First, we write the numbers in a way that their decimal points are aligned:
```
0.121000
+ 0.001210
+ 0.000121
```

### Step 2: Add the numbers
Now we can add them column by column, starting from the rightmost side:
```
0.121000
+ 0.001210
+ 0.000121
------------
```
Starting from the right:
- In the thousandths place: \(0 + 0 + 1 = 1\)
- In the hundredths place: \(0 + 1 + 2 = 3\)
- In the tenths place: \(1 + 0 + 0 = 1\)
- In the units place: \(0 + 0 + 0 = 0\)
- In the tenths place: \(0 + 0 + 0 = 0\)
- In the hundredths place: \(0 + 0 + 0 = 0\)

So, we have:
```
0.121000
+ 0.001210
+ 0.000121
------------
0.122331
```

### Step 3: Write the final answer
Thus, the sum of \(0.121 + 0.00121 + 0.000121\) is:
\[ \boxed{0.122331} \]