A box has a volume of 100 in³. If height = 5 in and width = 4 in, what is the length?

To find the length of the box, you can use the formula for the volume of a rectangular prism, which is given by:

[ \text{Volume} = \text{Length} \times \text{Width} \times \text{Height} ]

In this case, the volume is given as 100 in³, the height is 5 in, and the width is 4 in. You can rearrange the formula to solve for the length:

[ \text{Length} = \frac{\text{Volume}}{\text{Width} \times \text{Height}} ]

Substituting the known values into the formula gives:

[ \text{Length} = \frac{100}{4 \times 5} ]

Calculating the width times height:

[ 4 \times 5 = 20 ]

Then substituting this back into the fraction:

[ \text{Length} = \frac{100}{20} = 5 ]

Thus, the length of the box is 5 inches. This value matches the provided answer choice, indicating that it is the correct length based on the dimensions and volume provided.