7,77,77,777 + 77 equals

Options

A. 1111
B. 101001
C. 10101
D. 1010101

Answer

To solve the problem \( 7,77,77,777 + 77 \), we will follow these steps:

### Step 1: Write the numbers in a more manageable form
We can rewrite the numbers for clarity:
- \( 7,77,77,777 \) can be expressed as \( 7777777 \) (removing the commas).
- The number \( 77 \) remains as it is.

### Step 2: Align the numbers for addition
We will align the numbers vertically to perform the addition:
```
7777777
+ 77
```

### Step 3: Add the numbers column by column
Starting from the rightmost column:
- **Rightmost column**: \( 7 + 7 = 14 \). Write down \( 4 \) and carry over \( 1 \).
- **Next column**: \( 7 + 7 + 1 (carry) = 15 \). Write down \( 5 \) and carry over \( 1 \).
- **Next column**: \( 7 + 0 + 1 (carry) = 8 \). Write down \( 8 \).
- **Next column**: \( 7 + 0 = 7 \). Write down \( 7 \).
- **Next column**: \( 7 + 0 = 7 \). Write down \( 7 \).
- **Next column**: \( 7 + 0 = 7 \). Write down \( 7 \).
- **Leftmost column**: \( 0 + 0 = 0 \). Write down \( 0 \).

Putting it all together, we have:
```
7777777
+ 77
----------
7777854
```

### Final Result
Thus, \( 7,77,77,777 + 77 = 7,77,78,854 \).

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