Please help
with this !!!

What is the volume of a rectangular prism if the length is 10.4 mm the width is 5 mm in the height is 8 mm

Me because some of question i don’t understand

1- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis.2- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in the first question?