Two sets that contain the same number of elements are called_____

The question is based on the sets.

Answer: Two sets that contain the same number of elements are called equivalent sets.

Let's understand the size of a set or the cardinality of a set.

Explanation:

The number of elements in a set defines the cardinality of a set. For a set A, cardinality is defined as n(A). 

Suppose, set A = {1, 2, 3, 4, 5}, Hence, n(A) = 5.

Set B = {a, b, c, d, e}, Hence, n(B) = 5.

Then we can say that set A and set B are equivalent or of the same cardinality.

Thus, if n(A) = n(B), that means two sets that contain the same number of elements are known as equivalent sets.