🎯 ACT Flashcards — Part 3
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All Questions & Answers
Every question from ACT Practice Flashcard Test #3 with the correct answer and a short explanation, so you can review the full set without working through the interactive cards above.
MATH Q1. What is the formula for the volume of a rectangular prism (box)?
Answer:
V = length × width × height
Surface Area = 2(lw + lh + wh)
Example: A box 3×4×5 has volume = 60 cubic units.
💡 ACT often gives dimensions in different units — convert first before calculating.
MATH Q2. How do you solve a system of two linear equations?
Answer:
Method 1 — Substitution:
Solve one equation for a variable, substitute into the other.
Method 2 — Elimination:
Add or subtract equations to cancel one variable.
Check: plug solution back into BOTH equations.
💡 If the lines are parallel → no solution. If identical → infinite solutions.
MATH Q3. What is the difference between permutation and combination?
Answer:
Permutation: ORDER matters
nPr = n! / (n−r)!
Combination: ORDER does not matter
nCr = n! / [r!(n−r)!]
Example: Choosing 3 from 5 people for a podium = permutation (1st, 2nd, 3rd matter).
💡 ‘How many ways to arrange’ = permutation. ‘How many ways to choose’ = combination.
MATH Q4. What is the formula for simple interest?
Answer:
I = P × r × t
I = interest earned
P = principal (starting amount)
r = annual interest rate (as decimal)
t = time in years
Total amount = P + I
💡 ACT may give rate as a percentage — divide by 100 to convert to decimal first.
MATH Q5. What are the laws of exponents you must know for the ACT?
Answer:
xᵃ × xᵇ = xᵃ⁺ᵇ
xᵃ ÷ xᵇ = xᵃ⁻ᵇ
(xᵃ)ᵇ = xᵃᵇ
x⁰ = 1
x⁻ᵃ = 1/xᵃ
(xy)ᵃ = xᵃyᵃ
💡 Negative exponent = reciprocal. Fractional exponent = root: x^(1/2) = √x.
SCI Q6. What is the difference between a physical and chemical change?
Answer:
Physical change: changes form/shape but NOT chemical composition.
Examples: melting ice, cutting paper, dissolving sugar.
Chemical change: forms a NEW substance with different properties.
Examples: burning wood, rusting iron, baking a cake.
💡 Signs of chemical change: color change, gas produced, heat/light released, precipitate forms.
SCI Q7. What is the difference between acids and bases on the pH scale?
Answer:
pH scale: 0 to 14
pH < 7 = Acid (lemon juice, vinegar)
pH = 7 = Neutral (pure water)
pH > 7 = Base/Alkaline (baking soda, bleach)
Each pH unit = 10× difference in concentration.
💡 Acids donate H⁺ ions. Bases accept H⁺ ions (or donate OH⁻). ACT tests pH interpretation.
SCI Q8. What is the difference between conduction, convection, and radiation?
Answer:
Conduction: heat transfer through direct contact.
Example: touching a hot pan.
Convection: heat transfer through fluid movement.
Example: boiling water, ocean currents.
Radiation: heat transfer through electromagnetic waves.
Example: sunlight warming Earth.
💡 Only radiation can transfer heat through a vacuum (space). The others need matter.
SCI Q9. What is natural selection and how does it work?
Answer:
Natural selection: organisms with traits better suited to their environment survive and reproduce more.
4 conditions needed:
1. Variation in traits
2. Traits are heritable
3. Competition for resources
4. Differential survival/reproduction
💡 Evolution = change in allele frequency over time. Natural selection is the main mechanism.
SCI Q10. What is the difference between DNA and RNA?
Answer:
DNA: double-stranded, contains deoxyribose sugar, bases A-T-G-C, found in nucleus, stores genetic info.
RNA: single-stranded, contains ribose sugar, bases A-U-G-C (Uracil replaces Thymine), carries instructions for protein synthesis.
💡 DNA → RNA → Protein is the central dogma of molecular biology.
ENG Q11. What is the difference between active and passive voice?
Answer:
Active: subject performs the action.
Example: The dog chased the cat. ✓ (preferred)
Passive: subject receives the action.
Example: The cat was chased by the dog.
ACT prefers active voice — it is clearer and more concise.
💡 If the answer choice removes unnecessary words and uses active voice, it is usually correct.
ENG Q12. What is a misplaced modifier and how do you fix it?
Answer:
A misplaced modifier is placed too far from the word it describes, causing confusion.
Wrong: She almost drove her kids to school every day. (almost drove?)
Right: She drove her kids to school almost every day.
Fix: place the modifier directly next to what it modifies.
💡 Misplaced vs dangling: misplaced = modifier is there but in wrong place. Dangling = subject is missing.
ENG Q13. When should you use a colon (:) in a sentence?
Answer:
Use a colon after a complete independent clause to introduce:
• A list: I need three things: milk, eggs, bread.
• An explanation: She had one goal: to win.
• A quotation
NEVER use a colon after a verb or preposition.
💡 What comes BEFORE the colon must always be a complete sentence on its own.
ENG Q14. What is the correct use of ‘fewer’ vs ‘less’?
Answer:
Fewer: use with COUNTABLE nouns (things you can count)
Example: fewer students, fewer apples, fewer mistakes.
Less: use with UNCOUNTABLE nouns (mass/abstract)
Example: less water, less time, less effort.
💡 Quick test: Can you count it? → fewer. Can’t count it? → less.
ENG Q15. What does ‘conciseness’ mean in ACT English and why does it matter?
Answer:
Conciseness = expressing an idea in as few words as possible WITHOUT losing meaning.
ACT principle: if two answer choices are grammatically correct, the SHORTER one is usually right.
Eliminate: redundancy, wordiness, and unnecessary repetition.
💡 Watch for: ‘the reason is because’ (redundant), ‘at this point in time’ (wordy = just say ‘now’).
READ Q16. What is the difference between a ‘theme’ and a ‘topic’ in a literary passage?
Answer:
Topic: the subject matter — what the passage is ABOUT.
Example: Topic = grief
Theme: the deeper message or insight about that topic.
Example: Theme = grief can be a form of love and devotion.
ACT main idea questions often ask for the theme, not just the topic.
💡 Theme is always a complete idea/statement — not just a single word like ‘love’ or ‘loss’.
READ Q17. How should you approach a ‘paired passages’ question on the ACT?
Answer:
Paired passages present two texts on the same topic with different perspectives.
Strategy:
1. Read Passage A → answer Passage A questions
2. Read Passage B → answer Passage B questions
3. Then answer comparison questions
Focus on: agreement, disagreement, tone differences.
💡 Authors rarely fully agree — look for subtle differences in emphasis or approach.
READ Q18. What is ‘figurative language’ and what types appear on the ACT?
Answer:
Figurative language uses words beyond their literal meaning.
Key types:
• Simile: comparison using ‘like’ or ‘as’
• Metaphor: direct comparison without ‘like/as’
• Personification: giving human traits to non-human things
• Hyperbole: extreme exaggeration
• Symbolism: object represents a deeper idea
💡 ACT asks what figurative language SUGGESTS or IMPLIES — always connect back to context.
READ Q19. What is the difference between a ‘social science’ and ‘natural science’ passage on the ACT?
Answer:
Social Science: studies human behavior, society, history, psychology, economics.
Examples: Asch conformity study, education inequality research.
Natural Science: studies the physical and biological world.
Examples: coral reefs, monarch migration, gut microbiome.
Both use evidence-based arguments.
💡 Natural science passages often include data/graphs. Social science passages often include studies.
READ Q20. What strategy helps most with ACT Reading time management?
Answer:
Strategy: Read the passage first, then answer questions.
1. Skim for structure (1–2 min): first/last sentences of each paragraph.
2. Read questions — note line references.
3. Return to passage for evidence — don’t rely on memory.
4. Eliminate wrong answers — 2 are usually clearly wrong.
Time: ~8–9 minutes per passage.
💡 Never answer from memory alone — always verify with the text. The answer is always there.
Sources & References
Written and fact-checked by Dr Irfan Mansuri. External links open in a new tab and are provided for further reading and verification.
