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

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