Mathematics for IGCSE & O level - Number (Section 2)

1
Which of the following is the best example of a rational number?
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(C)
22/7
2
Which of the following numbers has the prime factorization 2 x 3 x 5 x 7?
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(A)
210
3
What is the lowest common multiple (LCM) of 6 and 8?
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(C)
24
4
Which number is a multiple of 7?
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(A)
21
5
If two numbers are relatively prime, what is their HCF?
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(B)
1
6
Which numbers are integers?
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A
C
7
Which of the following is an irrational number?
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(C)
π
8
Identify the correct statement:
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(B)
All natural numbers are integers.
9
Which of these expressions results in a rational number?
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(B)
2√2 x √2
10
What is the value of √64?
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(C)
8
11
Which of the following expressions results in a rational number?
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(B)
√2 x √2
12
Which number is a factor of 48, but not a factor of 36?
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(D)
8
13
What is the reciprocal of 4?
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(A)
1/4
14
Which of the following statements regarding the Highest Common Factor (HCF) and Lowest Common Multiple (LCM) is correct?
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(C)
The product of HCF and LCM of two numbers equals the product of the two numbers.
15
If a = 2^2 x 3 x 5 and b = 2 x 3^2 x 7, what is the HCF of a and b?
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(B)
12
16
What is the next prime number after 19?
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(B)
23
17
What is the HCF of 72 and 108?
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(C)
36
18
Which of the following is the same as 0.75?
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(C)
3/4
19
A number is divisible by both 2 and 3. What can you conclude about the number?
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(C)
It is divisible by 6.
20
What is the value of 3. 5 x 4 - 2?
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(C)
14
21
What is the smallest number that has factors of 2, 3, and 5?
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(C)
30
22
What is the value of 3^2 + 2^3?
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(B)
17
23
Which number is a prime number?
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(C)
17
24
Which of these numbers is both a factor of 60 and a multiple of 3?
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(B)
6
25
What is the result of 12 ÷ (3 + 1) x 2?
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(B)
6
26
Which of these numbers is not a factor of 27?
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(D)
6
27
Which number below is an irrational number?
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(C)
2.71828...
28
Which of the following statements is true?
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(B)
All natural numbers are integers.
29
What is the reciprocal of -3?
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(C)
-1/3
30
Which of the following is an example of a terminating decimal?
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(C)
5.81
31
Which of the following could be written as a fraction?
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(B)
0.333...
32
What is the value of k in 392k, given that 392k is a cube number?
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(B)
3
33
What is the product of prime factors of 27?
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(B)
3 x 3 x 3
34
What is the Highest Common Factor (HCF) of 50 and 64?
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(B)
2
35
If a number is rational, then it can be expressed as:
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(B)
A fraction a/b where a and b are integers and b ≠ 0
36
What is the product of prime factors of 72?
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(C)
2^3 x 3^2
37
What is the LCM of 27 and 63?
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(B)
189
38
What is the product of the prime factors of 25?
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(B)
5 x 5
39
What is the product of prime factors of 12?
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(C)
2 x 2 x 3
40
Which of the following can be written as a fraction?
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(D)
0.125
41
What is the product of prime factors of 198?
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(B)
2 x 3^2 x 11
42
What is the reciprocal of 2/3?
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(B)
3/2
43
Which of the following are the prime factors of 100?
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A
C
44
What is the Lowest Common Multiple (LCM) of 42 and 49?
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(C)
294
45
What is the highest common factor (HCF) of 8 and 12?
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(B)
4
46
What is the product of prime factors of 210?
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(A)
2 x 3 x 5 x 7
47
What is the product of prime factors of 350?
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(B)
2 x 5^2 x 7
48
What is the HCF of 2016 and 10584?
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(D)
336
49
Which is the product of prime factors of 100?
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(B)
2^2 x 5^2
50
What is the value of k in 96k, given that 96k is a square number?
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(C)
6