To calculate the surface area of a rectangular prism, you can use the formula:
\[ \text{Surface Area} = 2(lw + lh + wh) \]
where:
- \( l \) is the length,
- \( w \) is the width,
- \( h \) is the height.
In the given problem:
- Length (\( l \)) = 12 inches
- Width (\( w \)) = 5 inches
- Height (\( h \)) = 3 inches
Substituting these values into the surface area formula:
\[ \text{Surface Area} = 2(12 \times 5 + 12 \times 3 + 5 \times 3) \]
Calculating each term inside the parentheses:
- \( lw = 12 \times 5 = 60 \)
- \( lh = 12 \times 3 = 36 \)
- \( wh = 5 \times 3 = 15 \)
Now adding these values together:
\[ 60 + 36 + 15 = 111 \]
Now, multiplying by 2 to get the total surface area:
\[ \text{Surface Area} = 2 \times 111 = 222 \text{ square inches} \]
Thus, the surface area of the rectangular prism is 222 square inches.
The correct answer is:
222 square inches.