“Primary” means coming first or occurring first, so to solve this analogy, you have to determine which number is associated with the word “tertiary.” The correct answer is “three.” Although the prefix ­"ter-" is a little different than the prefix ­"tri-," they both mean related to the number three.

The prefix "mono­-" means related to the number one, and the prefix "poly-" means related to more than one or related to many. In this instance, that information would be enough for you to solve this problem. However, further clarification will be helpful for other problems. A “monosyllabic” word is a word that has one syllable, and a "polysyllabic" word is a word that has more than one syllable. So, "red" and "blue" are each monosyllabic words, and "yellow" and "color" are each polysyllabic words.

To be “charming” is to be pleasing in an attractive way. “Charming” is also the opposite of “repelling.” You can tell that the opposite of “attractive” is “unattractive,” as it has the prefix "un-," which usually adds the meaning not to a word. To help you, “disinterest” is a lack of concern or little concern, and “disarming” means tending to remove any feelings of unfriendliness or distrust,so it is similar to “charming.” “Contrary” means being the exact opposite of something else or not favorable or helpful, and “amoral” is having or showing no concern about whether behavior is morally right or wrong.

The key to linking these words is to look at their prefixes. “Overwhelmed” is to be overcome with feelings, whereas “underwhelmed” is to have a lack of feelings for something. The equivalent of pair of words for "educated" would be “overeducated” and “undereducated.” To further help you, if something is “educational,” it can be used to teach something, “uneducational” is the opposite of this. A person who is “educated” has learned information to a significant degree. If you are “re-educated,” you are taught the same information again or you are taught new information which is different from what you had previously been taught.

A “diameter” is a line running through the center of a circle from one side to the other. A “radius” is half the diameter, so to solve this analogy you have to determine which answer choice means half a circle. The correct answer is “semicircle.” The prefix "semi-" means half and the prefix "dia-" means through, across, over. To provide further help, the “circumference” is the length around the outside of a circle; a “sphere” is a three-dimensional circle; “parallel” means running alongside, having the same slope; “perpendicular” means running on opposite slopes and is the opposite of "parallel." 

“Infancy” is the state of being a baby. Similarly, "adolescence" is the state of transitioning from childhood to adulthood, or the state of being a "teenager."

The prefix "arachno-" means related to spiders and the suffix "-phobia" means fear of, so “arachnophobia” is a fear of spiders. The prefix "aqua-" means related to water, so “aquahobia” is a fear of water. 

The word fragment "-athl­-" suggests a sporting or exercise term and indeed a “triathlon” is a sporting competition with three events. The prefix "tri-" means three. Similarly, the prefix "dec-" means ten, so a “decathlon” is a sporting competition with ten events. 

The suffix "-archy" means ruling, so in a “patriarchy,” the people are ruled by a man or a group of men. In a "matriarchy," the people are ruled by a woman or a group of women.

The prefix "dys-" is a negation prefix; this means it takes the original meaning of the word “functional” (working) and causes it to mean the opposite, so “dysfunctional” means not working. To solve this analogy, then, you need to determine which of the answer choices means the opposite of “endorse.” “Endorse” means give support to, so the best available antonym is “undermine,” a word that means work to prevent someone from succeeding or something from occurring or working. None of the other answer choices work as antonyms of "endorse": "support" is a synonym of "endorse"; “demonstrate” means show someone or a group how to do something by example; “pretend” means fake; and “harangue” means rebuke, scold, or tell-off.