Here is a number machine.
What is the output when the input is 6?
Input →\to→ [×4\times 4×4] →\to→ [+5] → \to\,→ Output
Here is a different number machine.
Input →\to→ [+5] →\to→ [ . . . . . ] → \to\,→ Output
When the input is 15, the output is 4.
Complete the number machine.
