Lemonmath
Tiếng Việt

The exam format and how to tackle it

Lesson 7.1 · 25 min read · Updated

Two students each get 88 true/false statements right in Part II. Hà gets all 44 statements right in two questions and none in the other two. Nam gets 22 statements right in each of the four questions. Who scores more?

The answer lies in how Part II is marked, and it directly affects how you should work. This lesson describes the format of the specimen papers published by the Ministry of Education and Training from 2025, and the habits that stop you losing marks needlessly. The Ministry may adjust the format or the marking from year to year, so check its official announcement for your exam year.

Format and marking

The paper has three parts, lasts 9090 minutes, and is marked out of 1010.

Part Question type Questions Mark each Total
I Multiple choice (A, B, C, D) 1212 0.250.25 33
II True/false, each with 44 statements a), b), c), d) 44 up to 11 44
III Short answer 66 0.50.5 33

The mark rises steeply at the last statement: going from 33 to 44 correct doubles the mark. So every statement is worth checking carefully.

Back to the opening question: Hà scores 1+1=21+1=2, while Nam scores 4⋅0.25=14\cdot0.25=1. The same 88 correct statements, but Hà scores twice as much.

Part I: multiple choice

Each question has exactly one correct option and wrong answers lose nothing. So never leave a question blank. Part I questions are usually short and test one formula or one step.

Three quick methods:

  • Solve directly, then match with the options.
  • Work backwards: put each option into the condition of the question (for example, differentiate an option to check an antiderivative).
  • Eliminate: wrong options usually come from a familiar mistake (wrong sign, missing coefficient, wrong formula). Spotting the mistake lets you rule them out quickly.

Part II: true or false

Each question gives a common setting (a function, a figure, a data table) followed by four statements. Later statements are usually harder.

Part III: short answers and the 4 boxes

Each answer is one number, written on the sheet in 44 boxes. The minus sign and the decimal comma each take a box (the Vietnamese sheet uses a comma, not a point, as the decimal separator).

−0,5
Writing the answer −0.5-0.5 in 4 boxes

For example, 74=1.75\dfrac{7}{4}=1.75 is written 1,75 (all 44 boxes); −23-\dfrac{2}{3} to 1 decimal place is −0.7-0.7 (all 44 boxes).

Time plan and checking

9090 minutes for 2222 questions is tight. A suggested plan:

Task Suggested time
Part I (1212 questions) about 2020–2525 minutes
Part II (44 questions) about 2525–3030 minutes
Part III (66 questions) about 2525–3030 minutes
Checking, filling in the sheet about 55–1010 minutes

Work in order of difficulty, not necessarily in question order: on a first pass do every question you are sure of, mark the hard ones, then come back. Do not spend more than 55 minutes on one Part I question.

Use your scientific calculator to check: evaluate a function at given points, compute definite integrals, solve quadratic and cubic equations. The calculator catches slips, but you still need reasoning to know what to compute.

Key terms

Exercises

Each exercise comes with what you need and some steps to start. Try it yourself first, then open the solution.

Exercise 1 Multiple choice

In one true/false question you judge 33 statements correctly. What mark do you get for that question? A. 0.50.5. B. 0.750.75. C. 0.250.25. D. 11.

What you need and how to start

What you need: the Part II scale: 11, 22, 33, 44 correct statements give 0.10.1, 0.250.25, 0.50.5, 11.

Steps:

  1. Read off the mark for 33 correct statements.
Show solution

By the scale, 33 correct statements give 0.50.5. Option B is the mistake 3⋅0.253\cdot0.25.

Answer. A.

Exercise 2 Written answer

Bình gets 99 questions right in Part I; in Part II, 44, 44, 22, 11 statements right; in Part III, 33 questions right. Find Bình's mark.

What you need and how to start

What you need: Part I 0.250.25 per question; Part II by the scale; Part III 0.50.5 per question.

Steps:

  1. Work out each part.
  2. Add the three parts.
Show solution

Part I: 9⋅0.25=2.259\cdot0.25=2.25. Part II: 1+1+0.25+0.1=2.351+1+0.25+0.1=2.35. Part III: 3⋅0.5=1.53\cdot0.5=1.5.

Answer. 2.25+2.35+1.5=6.12.25+2.35+1.5=6.1.

Exercise 3 Short answer

A short-answer question asks for 1 decimal place, and the exact result is −23-\dfrac{2}{3}. What do you write in the 4 boxes? Why does the question not ask for 2 decimal places?

What you need and how to start

What you need: the minus sign and the comma each take a box.

Steps:

  1. Work out −23≈−0.667-\dfrac23\approx-0.667 and round to 1 decimal place.
  2. Count the characters if rounded to 2 decimal places.
Show solution

−23≈−0.667-\dfrac23\approx-0.667, which to 1 decimal place is −0.7-0.7: four characters "−", "0", ",", "7". To 2 decimal places it would be −0.67-0.67, which needs 55 boxes and cannot be written.

Answer. −0.7-0.7.

Exercise 4 Multiple choice

The horizontal asymptote of the graph of y=2x+1x−1y=\dfrac{2x+1}{x-1} is A. y=2y=2. B. x=1x=1. C. y=−1y=-1. D. x=2x=2.

What you need and how to start

What you need: a horizontal asymptote has the form y=by=b with b=lim⁡x→±∞yb=\lim\limits_{x\to\pm\infty}y.

Steps:

  1. Rule out the options of the form x=…x=\dots straight away.
  2. Find the limit as x→+∞x\to+\infty.
Show solution

Options B and D are vertical lines, so they are ruled out. lim⁡x→±∞2x+1x−1=2\lim\limits_{x\to\pm\infty}\dfrac{2x+1}{x-1}=2. Option C takes the ratio of the constant terms 1−1\dfrac{1}{-1}.

Answer. A.

Exercise 5 True/False

Given ∫02f(x) dx=3\displaystyle\int_0^2 f(x)\,dx=3 and ∫02g(x) dx=−1\displaystyle\int_0^2 g(x)\,dx=-1.

a) ∫02[f(x)+g(x)]dx=2\displaystyle\int_0^2\left[f(x)+g(x)\right]dx=2.

b) ∫022f(x) dx=6\displaystyle\int_0^2 2f(x)\,dx=6.

c) ∫20g(x) dx=1\displaystyle\int_2^0 g(x)\,dx=1.

d) ∫02f(x)g(x) dx=−3\displaystyle\int_0^2 f(x)g(x)\,dx=-3.

What you need and how to start

What you need: the integral of a sum is the sum of the integrals; a constant factor comes outside; swapping the limits changes the sign. There is no rule for the integral of a product.

Steps:

  1. Judge each statement with exactly one property.
Show solution

a) True: 3+(−1)=23+(-1)=2.

b) True: 2⋅3=62\cdot3=6.

c) True: swapping the limits changes the sign, −(−1)=1-(-1)=1.

d) False: the integral of a product is not the product of the integrals. For instance f(x)=32f(x)=\dfrac32 and g(x)=−x+12g(x)=-x+\dfrac12 satisfy the conditions, but ∫02f(x)g(x) dx=−32\displaystyle\int_0^2 f(x)g(x)\,dx=-\dfrac32.

Answer. a) True; b) True; c) True; d) False.

Exercise 6 Short answer

A car moves with velocity v(t)=3t2+2v(t)=3t^2+2 (m/s), with tt in seconds. Find the distance it travels in the first 33 seconds, in metres.

What you need and how to start

What you need: the distance is the integral of the velocity when v(t)≥0v(t)\ge0.

Steps:

  1. Write s=∫03(3t2+2) dts=\displaystyle\int_0^3(3t^2+2)\,dt.
  2. Use the antiderivative t3+2tt^3+2t.
Show solution

s=∫03(3t2+2) dt=[t3+2t]03=27+6=33.s=\int_0^3(3t^2+2)\,dt=\Big[t^3+2t\Big]_0^3=27+6=33.

Answer. 3333.

Exercise 7 Short answer

Two events AA, BB have P(A)=0.4P(A)=0.4, P(B∣A)=0.3P(B\mid A)=0.3 and P(B∣A‾)=0.5P(B\mid\overline{A})=0.5. Find P(B)P(B).

What you need and how to start

What you need: the law of total probability P(B)=P(A)P(B∣A)+P(A‾)P(B∣A‾)P(B)=P(A)P(B\mid A)+P(\overline A)P(B\mid\overline A).

Steps:

  1. Find P(A‾)=1−0.4P(\overline A)=1-0.4.
  2. Substitute into the formula.
Show solution

P(B)=0.4⋅0.3+0.6⋅0.5=0.12+0.3=0.42.P(B)=0.4\cdot0.3+0.6\cdot0.5=0.12+0.3=0.42.

Answer. 0.420.42.

Exercise 8 Challenge

Minh plans the 9090-minute paper: the last 55 minutes for checking, 22 minutes for each Part I question and 55 minutes for each Part III question. The remaining time is shared equally among the 44 Part II questions. How many minutes does each Part II question get?

What you need and how to start

What you need: Part I has 1212 questions and Part III has 66.

Steps:

  1. Work out the time for Parts I and III.
  2. Subtract everything from 9090 and divide by 44.
Show solution

Part I: 12⋅2=2412\cdot2=24 minutes; Part III: 6⋅5=306\cdot5=30 minutes. That leaves 90−5−24−30=3190-5-24-30=31 minutes for Part II, so 314=7.75\dfrac{31}{4}=7.75 minutes per question.

Answer. 7.757.75 minutes (about 77 minutes 4545 seconds).

Mini test

Mini test

Marked like the Vietnamese graduation exam: Part I 0.25 points per question; Part II up to 1 point per question (1, 2, 3, 4 correct statements give 0.1, 0.25, 0.5, 1 point); Part III 0.5 points per question.

Part I. Multiple choice

Question 1. The greatest possible mark for Part II is
Question 2. The minimum value of y=x2−4x+5y=x^2-4x+5 on [0,3][0, 3] is
Question 3. The result of a short-answer question is 73\dfrac73, to be given to 1 decimal place. You write
Question 4. The integral ∫013x2 dx\displaystyle\int_0^1 3x^2\,dx equals

Part II. True or false

Question 1. In Part II, a student judges 44, 33, 11, 00 statements correctly in the four questions.
a) The student gets 11 mark for the first question.
b) The student gets 0.750.75 for the second question.
c) The student gets 0.10.1 for the third question.
d) The student's total for Part II is 1.61.6.

Part III. Short answer

Question 1. A student gets 1111 questions right in Part I, exactly 33 statements right in every Part II question, and 33 questions right in Part III. What is the student's mark?

Question 2. Find ∫01ex dx\displaystyle\int_0^1 e^x\,dx. Give your answer to 2 decimal places.

Show answers and explanations
  1. Part I, question 1: A. Part II has 44 questions worth up to 11 mark each. Option B is the maximum for one question; option C is the total for Part I or Part III.
  2. Part I, question 2: A. y′=2x−4=0  ⟺  x=2∈(0,3)y'=2x-4=0\iff x=2\in(0, 3). Compare y(0)=5y(0)=5, y(2)=1y(2)=1, y(3)=2y(3)=2. Option B is y(3)y(3), from comparing only the endpoints.
  3. Part I, question 3: A. 73≈2.333\dfrac73\approx2.333; the second decimal digit is 3<53<5, so we round down to 2.32.3. C rounds to the wrong place, D to the nearest whole number.
  4. Part I, question 4: A. [x3]01=1\Big[x^3\Big]_0^1=1. Option C is the derivative 6x6x at x=1x=1; option D computes F(0)−F(1)F(0)-F(1).
  5. Part II, question 1: a) True; b) False; c) True; d) True. a) True: 44 correct statements give 11 mark. b) False: 33 correct statements give 0.50.5. c) True. d) True: 1+0.5+0.1+0=1.61+0.5+0.1+0=1.6.
  6. Part III, question 1: 6.25. Part I: 11⋅0.25=2.7511\cdot0.25=2.75; Part II: 4⋅0.5=24\cdot0.5=2; Part III: 3⋅0.5=1.53\cdot0.5=1.5. Total 6.256.25.
  7. Part III, question 2: 1.72. [ex]01=e−1≈1.718\Big[e^x\Big]_0^1=e-1\approx1.718, which rounds to 1.721.72.