Mathematics for IGCSE & O level - Number (Section 1)
1
Which of the following is a composite number?
Хариулт
(D)
12
2
Identify a pair of numbers where their HCF is 1.
Хариулт
(C)
7 and 10
3
What is the reciprocal of 1/5?
Хариулт
(B)
5
4
What is the simplified fraction for 0.5?
Хариулт
(A)
1/2
5
What are the prime factors of 42?
Хариулт
(A)
2, 3, 7
6
Which of the following is a prime number?
Хариулт
(C)
23
7
Which statement is true about the reciprocal of a number?
Хариулт
(B)
The reciprocal of a whole number is always a fraction.
8
Which of the following is the same as 0.666...
Хариулт
(B)
2/3
9
Which of the following statements are true regarding the highest common factor (HCF)?
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A
B
D
10
Which of the following are rational numbers?
Хариулт
A
C
D
11
A rectangle has dimensions 240 mm by 204 mm. What is the largest possible side length for identical squares that can cover the rectangle completely?
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(B)
12 mm
12
Which of these is a correct description of a rational number?
Хариулт
(B)
A number that can be expressed as a terminating or recurring decimal.
13
Which of the following is a common factor of 18 and 24?
Хариулт
(C)
3
14
What is the HCF of 12 and 15?
Хариулт
(B)
3
15
Which of the following is equivalent to 0. 25?
Хариулт
(C)
1/4
16
Which of the following is NOT a rational number?
Хариулт
(C)
√2
17
What is the reciprocal of -2?
Хариулт
(B)
-1/2
18
The prime factorization of 120 is 2^3 x 3 x 5. Based on this, which of the following is a factor of 120?
Хариулт
(C)
6
19
What are the prime factors of 28?
Хариулт
(B)
2, 2, 7
20
What are the prime factors of 18?
Хариулт
(B)
2, 3, 3
21
What is the LCM of 8 and 10?
Хариулт
(B)
40
22
What is the next number in the sequence: 2, 3, 5, 7, ...?
Хариулт
(D)
11
23
The HCF of two numbers is 7, and the LCM is 42. If one of the numbers is 14, what is the other number?
Хариулт
(C)
21
24
What type of number is √16?
Хариулт
(B)
Integer
25
Which statement about prime numbers is correct?
Хариулт
(C)
There are infinitely many prime numbers.
26
Which of the following numbers is NOT a factor of 36?
Хариулт
(D)
11
27
What is 5^2 - 3^2?
Хариулт
(B)
16
28
What is the LCM of 15 and 20?
Хариулт
(C)
60
29
What are the first four prime numbers?
Хариулт
(B)
2, 3, 5, 7
30
What is the lowest common multiple (LCM) of 4 and 6?
Хариулт
(B)
12
31
The HCF of two numbers is 5. The LCM of the same two numbers is 60. If one of the numbers is 15, what is the other number?
Хариулт
(A)
10
32
What is the prime factorization of 50?
Хариулт
(B)
2 x 5^2
33
What is the square root of 144?
Хариулт
(B)
12
34
If a bus leaves a station every 40 minutes and a train leaves the same station every 45 minutes, at what time will they next leave the station together, assuming they both left the station at 7:00 am?
Хариулт
(A)
10:00 am
35
What is the value of √81?
Хариулт
(B)
9
36
What is the HCF of 16 and 24?
Хариулт
(C)
8
37
What is the highest common factor (HCF) of 24 and 36?
Хариулт
(B)
12
38
The HCF of two numbers is 3. The LCM of the same two numbers is 18. If one number is 6, what is the other number?
Хариулт
(C)
9
39
What is the product of the prime factors of 30?
Хариулт
(B)
30
40
What is the prime factorization of 72?
Хариулт
(C)
2^3 x 3^2
41
Which number has the prime factors 2, 3, and 5?
Хариулт
(C)
30
42
Which of the following is an example of a recurring decimal?
Хариулт
(B)
0.333...
43
Two lighthouses flash at intervals of 22 seconds and 16 seconds, respectively. If they flash together at 10:00 PM, when will they next flash together?
Хариулт
(B)
10:04 PM
44
Which of the following sets of numbers are all natural numbers?
Хариулт
(B)
1, 2, 3, 4
45
Which of the following is NOT a property of prime numbers?
Хариулт
(C)
They are all odd numbers.
46
What is the reciprocal of 2/3?
Хариулт
(C)
3/2
47
What is the name for a number that cannot be written as a fraction?
Хариулт
(C)
Irrational number
48
Which of the following numbers is NOT a natural number?
Хариулт
(A)
0
49
Which set of numbers are all integers?
Хариулт
(B)
-3, 0, 5, 9
50
If the LCM of two numbers is 36 and their HCF is 6, which of the following pairs could be the two numbers?
