QUESTIONS 1 TO 10 ARE WORTH
3 MARKS EACH
4. Evaluate
100 − 99 + 98 − 97 + 96 − 95 + ⋯
+4−3+2−1
1. Find the value of 𝑚 in
(A) 48
(B) 49
(C) 50
(D) 99
(E) 100
1 + 2 + 3 + 4 + ⋯ + 𝑚 = 253
(A) 20
(B) 21
(C) 22
(D) 23
(E) 24
5. A new operation is defined as
𝑚 ※ 𝑛 = (𝑚 + 𝑛) ÷ 2
2. Shawn and Matthew have 76 books
altogether. The number of books
Shawn has is 3 times the number of
books of Matthew has. How many
books does Shawn have?
Find the value of 3 ※ (6 ※ 8)
(A)
(B)
(C)
(D)
(E)
(A) 19
(B) 27
(C) 47
(D) 57
(E) None of the above
3
4
5
6
7
6. A whole number 𝑛 is multiplied by 6. 6
is then added to this product, after
which the sum is divided by 6. Finally,
6 is subtracted from the quotient,
3. Find, in 𝑚2 , the area of the shaded
which still gives a value of 6. Find the
region.
value of 𝑛.
9m
1m
1m
(A)
(B)
(C)
(D)
(E)
6m
(A) 17
(B) 19
(C) 35
(D) 54
(E) None of the above
SEAMO 2021 Paper B
1
10
11
12
13
14
7. Some teenagers are being questioned 10. Find the number of ways for an insect
by the traffic police.
to climb from Point 𝐴 to Point 𝐶 , by
passing through Point 𝐵.
Adrian: I have a driving license.
Ben: I do not know how to drive.
Chris: Ben does not know how to
drive.
Given that only one person is telling
the truth, which of the following
conclusions can we make?
(A) Both Adrian and Ben can drive
(B) Both Ben and Chris can drive
(C) Only Adrian can drive
(D) Ben cannot drive
(E) Chris cannot drive
(A) 8
(B) 9
(C) 10
(D) 11
(E) 12
8. There are 19 chickens, ducks and
goats on a farm. The farmer counted
56 animal legs altogether. How many
goats are there?
QUESTIONS 11 TO 20 ARE WORTH
4 MARKS EACH
11. The average of 5 whole numbers is
20. When one of the numbers is
changed to 18, the new average is
now 18. What is the original value of
that number?
(A) 10
(B) 9
(C) 8
(D) 7
(E) 6
(A) 26
(B) 28
(C) 30
(D) 32
(E) 34
9. The teacher wanted to distribute 100
apples as fairly as possible to the
children at a nursery. At least one of
the children received 3 apples. What
could be the maximum number of
children at the nursery?
(A) 36
(B) 47
(C) 49
(D) 51
(E) 53
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SEAMO 2021 Paper B
12. The fruit seller is packing oranges 15. Find ∠𝑎 + ∠𝑏 + ∠𝑐 + ∠𝑑.
into some bags. If he packs 5
oranges into each bag, he has 14
oranges leftover. If he packs 7
oranges into each bag, he will need
another 2 bags.
How many oranges does the fruit
seller have?
(A) 76
(B) 78
(C) 80
(D) 82
(E) 84
(A) 180∘
(B) 270∘
(C) 360∘
(D) 450∘
(E) None of the above
13. Find the value of
(
1
1
1
+
+
+⋯
1×2 2×3 3×4
1
+
) × 2022
2021 × 2022
16. Find the missing number
40
45
29
( )
(A) 2020
(B) 2021
(C) 2022
(D) 2023
(E) None of the above
24
19
5
15
8
13
12
17
(A) 49
(B) 50
(C) 51
(D) 52
(E) 53
14. Find the value of ̅̅̅̅
𝐴𝐵 in
17. Find the remainder when
−
𝐴
𝐵
𝐵 𝐶
𝐶 𝐴
𝐴 𝐵
555 … 55
⏟
2021 5's
is divided by 13.
(A) 32
(B) 38
(C) 44
(D) 54
(E) 65
SEAMO 2021 Paper B
(A) 5
(B) 3
(C) 9
(D) 4
(E) 6
3
18. 4 triangles are formed using 9 line 20. How many rectangles are there in the
segments of equal lengths. If 4 beads
figure?
are to be put along each line
segment at equal intervals, how
many beads will there be altogether?
(A) 22
(B) 24
(C) 25
(D) 26
(E) 27
(A) 20
(B) 21
(C) 22
(D) 24
(E) 25
QUESTIONS 21 TO 25 ARE WORTH
6 MARKS EACH
19. Javier was walking home using the 21. In Mathematics,
path indicated by the arrows.
12 = 1 × 1 = 1
22 = 2 × 2 = 4
32 = 3 × 3 = 9
…
…
120 m
70 m
It is also observed that
22 = 12 + 3
32 = 22 + 5
42 = 32 + 7
52 = 42 + 9
…
…
2
21 = 𝑎2 + 𝑏
What was the total distance, in
metres, he had covered by the time
he reached home?
(A) 70
(B) 95
(C) 120
(D) 190
(E) None of the above
Find the value of (𝑎 + 𝑏).
4
SEAMO 2021 Paper B
22. The figure shows a number pattern 24. Mdm Yee has 10 apples to give to her
within an array of hexagons. In the
3 children. Each child must get at
middle, there is only one dot. There
least one apple.
are 6 dots on the 1st hexagon. There
are 12 and 18 dots on the 2 nd and
How many ways are there to do so?
3rd hexagons, respectively.
How many dots are there in the 49 th
25. Megan was walking along a straight
hexagon?
road. She met an oncoming car and
she asked the driver, “Did you
overtake a cyclist just now?”
“Yes, 10 minutes ago,” the driver
replied.
After walking for another 10 minutes,
Megan met the cyclist.
Given that the cyclist’s speed was
4 times Megan’s walking speed, how
many times of Megan’s speed was the
driver’s speed?
23. There are 1, 4 and 10 cubes in
Figures 1, 2 and 3, respectively.
End of Paper
Fig 1
Fig 2
Fig 3
How many cubes are there altogether in
Figures 1 to 5?
SEAMO 2021 Paper B
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