Experience the Quality With Free PSAT 8/9 Exam Questions That Helps Candidates Pass

30% of 120 = 0.30×120=360.30 \times 120 = 36. Option B correct. Option A confuses 25%. Option C reflects one-third (33%). Option D miscalculates. On PSAT, translate percents into decimals and multiply carefully.

Subtract 8x8x: 6x−10=86x - 10 = 8. Add 10: 6x=186x = 18. Divide: x=3x = 3. Option A correct.

Use inclusion-exclusion: 20+15−5=3020+15-5=30. Wait, total = 30, not 35. Careful! The formula is ∣A∪B∣=∣A∣+∣B∣−∣A∩B∣|A\cup B|=|A|+|B|-|A\cap B|. So 20+15−5=3020+15-5=30. Option B is correct. Check logic: 5 counted twice, subtract once. Thus 30 students take at least one.

Standard English Conventions questions test grammar, usage, and sentence mechanics. The subject is “collection,” a singular noun, not “artifacts.” Prepositional phrases like “of artifacts from the region” do not change the number of the subject. Therefore the verb must be singular: “demonstrates.” Option B correctly matches the singular subject with a singular verb (subject-verb agreement). Option A incorrectly uses the plural verb “demonstrate.” Option C changes the verb form to a participle and would create a fragment unless additional structure followed. Option D shifts the tense to past (“demonstrated”), which may be incorrect if the sentence presents a timeless fact about the collection. A reliable strategy is to cross out the prepositional phrase to reveal the core subject-verb pair: “The collection ___ demonstrates…” This helps avoid the common trap of agreeing the verb with the noun closest to it rather than the true subject.

The subject is “group,” singular. Correct verb is “was.” Option B correct.