Answer: The required expression is,

Step-by-step explanation:
Given,
The number of boxes Ray has = 3,
The number of layers of chocolate each box has = 4,
⇒ The total number of layers of chocolates = 4 × 3,
Now, Each layers has 4 rows of chocolate,
⇒ The total number of rows of chocolate = 4 × 4 × 3,
Also, Each row has 4 chocolates,
So, the total number of chocolates = 4 × 4 × 4 × 3,
He distributes these chocolates to his 16 friends,
Hence,


Which is the required expression.