"Students" is plural, so the plural word "fans" should be used in the sentence. However, the word used in the sentence as it is written is the singular “fan,” which is incorrect. 

This sentence's error is a discrepancy in number. Two children are mentioned, "Jordan and Marvin," so logically, they would grow up to become two different lawyers. The sentence uses the singular noun "a lawyer" where it should use the plural noun "lawyers," so "lawyer" is the correct answer.

The corrected sentence reads, "Jordan and Marvin’s mother has decided that they will become lawyers when they grow up, but they seem more artistically inclined."

This sentence's error is a problem with agreement of plurals. Multiple "caterpillars" should form multiple cocoons, but the sentence uses the singular noun "a cocoon," which doesn't make sense. "A cocoon" is thus the correct answer, and the corrected sentence reads, "As part of their development, caterpillars form cocoons and eventually emerge as moths or butterflies."

As with pronouns, when a noun or group of nouns is replaced in a sentence by another noun, they must agree in number. The multiple subjects "Dedication," "work," and "attention" call for a plural word.  A simple correction would be "important factors"

In this sentence, there are two individuals, both painters, so the object should reflect that number. The corrected sentence reads, "Frida Kahlo and her husband Diego Rivera were both well-known and talented Mexican painters."

This sentence lacks agreement between nouns. Since there are many aliens, “savior” should be plural. The corrected sentence reads, "Recognizing that the inhabitants of Earth suffered from many wars, disasters, and diseases, the aliens hoped to be welcomed as saviors."

It is clear from the content of this sentence that Jeremy and Joe each have their own car, but the sentence has “car” as singular. This should be plural to avoid confusion. The corrected sentence reads, "At the end of the day, Jeremy and Joe said goodbye to each other, got into their cars, and drove their separate ways."

There is a discrepancy in the agreement of nouns in this sentence. "Reading, writing and arithmetic" require the plural form of "skill," "skills." Multiple subjects require a plural predicate to match their form. "Reading, writing, and arithmetic" are not being discussed as a unified group (which is an exception requiring a singular predicate), so the agreement must be plural, because several subjects are being discussed.

This sentence's error is one that has to do with the logic of conjunctions. The conjunction "and" is used to join two sentences that do not contradict each other. This is not the case with these two sentences: based on the first sentence, you would think that the speaker would only be allowed to check out three books, but this is not the case. So, "and" is not the correct conjunction to use; changing "and" to "but" would correct the sentence's error.

This sentence begins with "I would bake more cookies" but then the speaker gives a reason why he or she does not bake more cookies, "every time [he or she] tries to bake cookies, [his or her] oven burns them." So, "and" is not the correct conjunction to use in this sentence. A conjunction like "but" is needed to contrast the two parts of the sentence and convey why the speaker does not bake more cookies even though he or she "would."