In the expression 4:8::2:4, which terms are considered the extremes?

In the given expression 4:8::2:4, which is a ratio comparison, the extremes are the first and last terms of the ratios. In this case, 4 and 4 are at the ends of the expression.

This means that in the relationship "4 is to 8 as 2 is to 4," the numbers that function as extremes are connected by the ratios being compared. The first extreme is the first term of the first ratio (4), and the second extreme is the last term of the second ratio (4).

Identifying extremes is essential in understanding how ratios and proportions work, as they help in establishing the relationship interlinked through the ratios. The other options allude to individual numbers or specific pairs that do not encompass the concept of extremes as defined in the ratio. Instead, the correct understanding correctly identifies the pairs at the extremes of the relationship represented in the expression.