The variables are the number of handbags and the time.
*The width in your question - I assumed it is refers to the height of the triangle base.
Volume of a triangle prism = base area x height
The base is a triangle:
Volume of a triangle prism = (1/2 x base x height₁) x height₂
Plug in the values and solve for height₂:
50.4 = (1/2 x 9 x 3.5) x height
50.4 = 15.75 x height
height = 50.4 ÷ 15.75
height = 3.2 units
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Answer: Height = 3.2 units
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Subtract 6.7 from 20. This is 13.3. Divide 13.3/5 is 2.66. That is the answer