Secondary 3 G2 Mathematics Tutor Bukit Timah | Simple and Compound Probability Tables. Did you know? A two-way table can reveal probabilities that a single total hides.
This Secondary 3 G2 Mathematics tutor guide for Bukit Timah students gives quick explanations and worked examples of simple and compound probability tables. Use the current school syllabus and lesson sequence to select relevant exercises.
Simple probability
In a fictional class of 30 students, 18 choose option A. The probability that a randomly selected student chooses A is 18/30=3/5.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
Two-way table
Suppose 12 boys and 18 girls are surveyed. Seven boys and eleven girls choose A, giving 18 choosing A in total.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
Joint event
The probability of selecting a girl who chooses A is 11/30, because eleven students satisfy both conditions.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
Conditional probability
Among the eighteen girls, eleven choose A. Thus the fraction of girls choosing A is 11/18, not 11/30.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
Either group
If categories ‘boy’ and ‘girl’ are exclusive under this fictional survey’s classification, the chance of choosing one or the other is 30/30=1.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
Independent draws
If two selections are made with replacement from the same thirty students, the probability of A on both is (18/30)²=9/25 under independent selection.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
Check
Write the denominator in words: whole class, girls only or a second-stage remaining group. This prevents many probability mistakes.
A useful tutoring check is to change one part of the question and ask the learner to explain whether the same method still applies. The first mistaken step is more informative than a final wrong answer.
Seven-day revision plan
Day 1: define the quantities and symbols. Day 2: reproduce a worked example with reasons. Day 3: change the values. Day 4: solve a mixed question without a method label. Day 5: repair the first mistake. Day 6: connect the skill with another chapter. Day 7: complete an independent retest.
Frequently asked questions
What should I check first? Identify the question’s given information and requested quantity. How do I verify the answer? Substitute it into the original relationship or diagram. Why might the calculation be correct but the answer wrong? A mistaken reference point, denominator or unit can change the question being answered.
Official syllabus and small-group tutorial context
Consult the 2027 SEC G2 Mathematics K210 syllabus for exact assessment scope. The unchanged eduKateSG three-pupil Mathematics tutorial reference describes the existing learning model near Sixth Avenue. Confirm current Secondary 3 G2 tutor, class suitability, fees, venue and timetable directly.
Related Secondary 3 G2 Mathematics guides
Read Angles of Elevation and Depression, Probability Rules and Linear Graph Intersections.