Let's evaluate each statement one by one.
### Statement #1:
\[ 3 \cdot 20 = 4(6 + 9) \]
Calculating the left side:
\[ 3 \cdot 20 = 60 \]
Calculating the right side:
\[ 6 + 9 = 15 \]
\[ 4 \cdot 15 = 60 \]
So, both sides are equal:
\[ 60 = 60 \]
**Statement #1 is true.**
### Statement #2:
\[ 4 \cdot 12 = 6 \cdot (8 \cdot 2) \]
\[ 12 + 6 \cdot \sqrt{64} = 2 \cdot 4 \cdot 8 \]
Calculating the first part of the statement:
Left side:
\[ 4 \cdot 12 = 48 \]
Right side:
\[ 8 \cdot 2 = 16 \]
\[ 6 \cdot 16 = 96 \]
Now comparing:
\[ 48 \neq 96 \]
So the first part is **false**.
Calculating the second part:
Left side:
\[ 12 + 6 \cdot \sqrt{64} = 12 + 6 \cdot 8 = 12 + 48 = 60 \]
Right side:
\[ 2 \cdot 4 \cdot 8 = 64 \]
Comparing:
\[ 60 \neq 64 \]
So the second part is also **false**.
**Statement #2 is false.**
### Statement #3:
\[ 4 \cdot 18 - 4 \cdot 6 = 42 + 4 \cdot 8 \]
Calculating the left side:
\[ 4 \cdot 18 = 72 \]
\[ 4 \cdot 6 = 24 \]
\[ 72 - 24 = 48 \]
Calculating the right side:
\[ 4 \cdot 8 = 32 \]
\[ 42 + 32 = 74 \]
Comparing both sides:
\[ 48 \neq 74 \]
**Statement #3 is false.**
### Conclusion:
The only true statement is Statement #1. Therefore, the correct responses would be **1 only**.