Mathematics for IGCSE & O level - Number (Section 3)

  • 1
    What is the LCM of 84 and 180?
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    (C)
    1260
  • 2
    What is the value of k in 96k, given that 96k is a square number?
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    (C)
    6
  • 3
    Which of the following is a rational number?
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    (D)
    0.46
  • 4
    If two lighthouses flash every 22 and 16 seconds, at what time will they flash together again if they flashed at 10 pm?
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    (C)
    10:04:48
  • 5
    What is the lowest common multiple (LCM) of 20 and 50?
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    (C)
    100
  • 6
    What is the HCF of 5544 and 2268?
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    (D)
    168
  • 7
    Which of the following numbers is a prime number?
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    (C)
    11
  • 8
    Buses to Shenley leave every 40 minutes and buses to Winley leave every 15 minutes. If buses to both places leave at 8.15 a.m., when is the next time they leave at the same time?
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    (D)
    9.45 a.m.
  • 9
    What is the reciprocal of 1/4?
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    (B)
    4
  • 10
    What is the HCF of 84 and 180?
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    (C)
    12
  • 11
    What is the value of k in 392k, given that 392k is a cube number?
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    (B)
    3
  • 12
    What is the LCM of 45, 60, and 75?
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    (B)
    900
  • 13
    Which of the following is a prime number?
    คำตอบ
    (C)
    23
  • 14
    Which of the following is an Irrational Number?
    คำตอบ
    (D)
    √12
  • 15
    What is the value of k in 96k, given that 96k is a cube number?
    คำตอบ
    (B)
    3
  • 16
    Find the largest possible side length for squares, given that a rectangle measures 240mm by 204mm.
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    (D)
    12 mm
  • 17
    What is the next time that the lights flash at the same time if the lights flash every 22 and 16 seconds respectively? Both lights switched on at 10 p.m.
    คำตอบ
    (B)
    10:04:48 p.m.
  • 18
    What is the result of expressing 0.666... as a fraction?
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    (B)
    2/3
  • 19
    Which of the following are common multiples?
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    B
    D
  • 20
    Find the largest possible side length for the identical squares that will make up a 240 mm by 204 mm rectangle.
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    (C)
    12 mm
  • 21
    Which of the following numbers is NOT a natural number?
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    (C)
    0
  • 22
    Which is the product of prime factors of 144?
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    (C)
    2^4 x 3^2
  • 23
    Which of the following statements are true about a common factor of two numbers?
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    A
    D
  • 24
    What is the HCF of 260 and 300?
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    (B)
    10
  • 25
    What do you call the largest number that is a factor of two or more numbers?
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    (B)
    Highest Common Factor
  • 26
    Which of the following best describes an Irrational number?
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    (C)
    A number that cannot be written as a fraction.
  • 27
    Which of the following numbers is a prime number?
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    (C)
    17
  • 28
    Which of the following is NOT a common multiple of 2 and 5?
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    (D)
    15
  • 29
    What is the HCF of 45, 60, and 75?
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    (C)
    15
  • 30
    What do you call the smallest number that is a multiple of two or more numbers?
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    (D)
    Lowest Common Multiple
  • 31
    What is the lowest common multiple (LCM) of 2 and 5?
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    (D)
    10
  • 32
    What is the highest common factor (HCF) of 20 and 50?
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    (C)
    10
  • 33
    What is the highest common factor (HCF) of 48 and 84?
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    (C)
    12
  • 34
    If the HCF of two numbers is 4, which of the following could be the two numbers?
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    (B)
    12 and 20
  • 35
    Which of the following is NOT a rational number?
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    (C)
    π
  • 36
    Which of the following is an example of a natural number?
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    (C)
    1
  • 37
    Which of the following is NOT a factor of 24?
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    (D)
    7
  • 38
    Which set of numbers contains only natural numbers?
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    (C)
    {1, 2, 3, 4}
  • 39
    What is the reciprocal of 7/5?
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    (B)
    5/7
  • 40
    What are the prime factors of 55?
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    (A)
    5, 11
  • 41
    The prime factors of 20 are:
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    (B)
    2, 2 and 5