Calculate X: Finding Width in a 3×5×X Rectangular Prism with Volume 90 cm³

To find the missing width ($X$) of the rectangular prism, we start with the volume formula for a rectangular prism:

$V = l \times w \times h$

Here, $l = 3 \, \text{cm}$, $h = 5 \, \text{cm}$, and $V = 90 \, \text{cm}^3$. We need to find $w$ (or $X$).

Substitute the known values into the formula:

$90 = 3 \times X \times 5$

Simplifying, we have:

$90 = 15 \times X$

To solve for $X$, divide both sides of the equation by 15:

$X = \frac{90}{15}$

Calculating this gives:

$X = 6$

Therefore, the calculated width of the rectangular prism is $X = 6 \, \text{cm}$.