Answer:
Given the statement: The length of an aquarium, which has the form of a rectangular solid, is equal to 5 decimeters, and the width is 4/5 the length.
Since, aquarium is in the form of a rectangular solid.
Length of an aquarium(l) = 5 dm
Width of an aquarium(w)=
It is also given that when you put 40 liters of water into the aquarium, it was full to its volume.
Volume of Rectangular solid(V) is given by;
where l is the length , w is the width and h is the height of the rectangle respectively.
Volume(V) of an aquarium = liter.
Using volume formula to calculate the height(h);
Divide both sides by 20 we get;
h = 3 dm [ 1 liter = 1 cubic dm]
We have to find the what part of length makes up the height of the aquarium.
where l = 5 dm
therefore, part of the length makes up the height of the aquarium.