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SEAMO 2027 - Paper A - SET 12 - Self-study

Question 1

SEAMO self-study edition 2027; not an official 2027 paper. Original source years are retained. 25 questions, 90 minutes; Q1–10: 3 points, Q11–20: 4 points, Q21–25: 6 points, total 100. Original response types and all subparts are preserved. Verified is an editorial convention; source defects, necessary assumptions and unresolved mathematical uncertainty are disclosed.

Find the value of the star in the picture.

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  1. 5
  2. 6
  3. 7
  4. 8
  5. None of the above

Question 2

How many ways are there to spell “SUGAR” along the lines in the diagram?

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  1. 3
  2. 5
  3. 6
  4. 9
  5. 10

Question 3

Find the value of 9 + 99 + 999.
  1. 1107
  2. 1108
  3. 1109
  4. 1110
  5. None of the above

Question 4

Find the missing number in the diagram.

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  1. 12
  2. 13
  3. 14
  4. 15
  5. 16

Question 5

Shawn is 8 years old. His mother is 33 years old. In how many years will the sum of their ages be 57?

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  1. 6
  2. 7
  3. 8
  4. 9
  5. 10

Question 6

Find the sum of the first 42 numbers in the repeating sequence 2,4,6,2,4,6,2,4,6,…

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  1. 168
  2. 164
  3. 162
  4. 160
  5. 172

Question 7

How many cubes are there in the model below?

Count the solid triangular stack shown, including the cubes needed directly underneath to support it. Assume no gaps in those columns and no extra cubes outside this stack.

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  1. 8
  2. 9
  3. 10
  4. 11
  5. 12

Question 8

A farm has 18 chickens and rabbits altogether, with 58 legs in total. How many rabbits are there?

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  1. 8
  2. 9
  3. 10
  4. 11
  5. 12

Question 9

Evaluate all four expressions.

(a) 12 + 13 + 8 + 10

(b) 18 + 13 + 22 + 28

(c) 18 + 28 + 38

(d) 16 + 17 + 18 + 19

Give answers to (a), (b), (c) and (d), with the part labels. All four parts are manually graded; no explanation is required for full credit.

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Question 10

Find the missing numbers m and n.

Use the same simple arithmetic relation in all four diagrams, inferred from the two completed ones.

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  1. 7 and 8
  2. 8 and 9
  3. 8 and 8
  4. 7 and 9
  5. 10 and 3

Question 11

There are 20 chickens and cows altogether on a farm. The farmer counts 48 legs. How many more chickens than cows are there?
  1. 8
  2. 9
  3. 10
  4. 11
  5. 12

Question 12

Find the missing number.

Continue the same simple arithmetic relation shown by the two completed diagrams.

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  1. 16
  2. 17
  3. 18
  4. 19
  5. 20

Question 13

Which diagram comes next? The five choices A–E are shown below.

For this practice question, choose the option that continues the common relationship between internal straight line segments and dots. Ignore the outer square borders; treat each branch ending at an intersection as a separate segment. The original prompt does not specify its rule and the source provides no key.

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  1. Diagram A
  2. Diagram B
  3. Diagram C
  4. Diagram D
  5. Diagram E

Question 14

There are 7 days in a week. If today is Tuesday, on which day of the week is the 100th day from today?

Counting convention: count today as day 1, as intended by the source answer keys.

Enter a full weekday name in English or Vietnamese with accents, without an explanation. Automatic text checking uses listed spellings only. An unsupported/null result is ungraded and requires manual checking; it does not mean the answer is wrong.

Question 15

There are four steps in a staircase. Cindy may climb one step or two steps at a time. How many ways can she climb the staircase?

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Question 16

Evaluate \(1+2+3+\cdots+9+10+9+8+\cdots+2+1\).
  1. 89
  2. 90
  3. 99
  4. 100
  5. None of the above

Question 17

Tom has to paint a 46 m long fence. On the first day, he paints 10 m of it. Each day after that, he paints 1 m less than the day before. How many days does it take him to finish painting the fence?
  1. 4
  2. 5
  3. 6
  4. 7
  5. 8

Question 18

Use a simple method to compute 88×5+88×4+88×1.

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  1. 576
  2. 764
  3. 880
  4. 888
  5. 889

Question 19

Observe the two clocks below. How much time has passed?

Use the next occurrence of the second clock reading after the first, with no extra twelve-hour turns.

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  1. 1 h 45 min
  2. 2 h
  3. 2 h 15 min
  4. 3 h
  5. 3 h 15 min

Question 20

Which two balls, one from Group A and one from Group B, should be switched so that the sums of the numbers in the two groups are equal?

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  1. 45 with 40
  2. 33 with 39
  3. 33 with 27
  4. 45 with 39
  5. None of the above