Mathematics for IGCSE & O level - Number (Section 1)
1
Which of the following is a composite number?
Відповідь
(D)
12
2
Identify a pair of numbers where their HCF is 1.
Відповідь
(C)
7 and 10
3
What is the reciprocal of 1/5?
Відповідь
(B)
5
4
What is the simplified fraction for 0.5?
Відповідь
(A)
1/2
5
What are the prime factors of 42?
Відповідь
(A)
2, 3, 7
6
Which of the following is a prime number?
Відповідь
(C)
23
7
Which statement is true about the reciprocal of a number?
Відповідь
(B)
The reciprocal of a whole number is always a fraction.
8
Which of the following is the same as 0.666...
Відповідь
(B)
2/3
9
Which of the following statements are true regarding the highest common factor (HCF)?
Відповідь
A
B
D
10
Which of the following are rational numbers?
Відповідь
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?
Відповідь
(B)
12 mm
12
Which of these is a correct description of a rational number?
Відповідь
(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?
Відповідь
(C)
3
14
What is the HCF of 12 and 15?
Відповідь
(B)
3
15
Which of the following is equivalent to 0. 25?
Відповідь
(C)
1/4
16
Which of the following is NOT a rational number?
Відповідь
(C)
√2
17
What is the reciprocal of -2?
Відповідь
(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?
Відповідь
(C)
6
19
What are the prime factors of 28?
Відповідь
(B)
2, 2, 7
20
What are the prime factors of 18?
Відповідь
(B)
2, 3, 3
21
What is the LCM of 8 and 10?
Відповідь
(B)
40
22
What is the next number in the sequence: 2, 3, 5, 7, ...?
Відповідь
(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?
Відповідь
(C)
21
24
What type of number is √16?
Відповідь
(B)
Integer
25
Which statement about prime numbers is correct?
Відповідь
(C)
There are infinitely many prime numbers.
26
Which of the following numbers is NOT a factor of 36?
Відповідь
(D)
11
27
What is 5^2 - 3^2?
Відповідь
(B)
16
28
What is the LCM of 15 and 20?
Відповідь
(C)
60
29
What are the first four prime numbers?
Відповідь
(B)
2, 3, 5, 7
30
What is the lowest common multiple (LCM) of 4 and 6?
Відповідь
(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?
Відповідь
(A)
10
32
What is the prime factorization of 50?
Відповідь
(B)
2 x 5^2
33
What is the square root of 144?
Відповідь
(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?
Відповідь
(A)
10:00 am
35
What is the value of √81?
Відповідь
(B)
9
36
What is the HCF of 16 and 24?
Відповідь
(C)
8
37
What is the highest common factor (HCF) of 24 and 36?
Відповідь
(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?
Відповідь
(C)
9
39
What is the product of the prime factors of 30?
Відповідь
(B)
30
40
What is the prime factorization of 72?
Відповідь
(C)
2^3 x 3^2
41
Which number has the prime factors 2, 3, and 5?
Відповідь
(C)
30
42
Which of the following is an example of a recurring decimal?
Відповідь
(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?
Відповідь
(B)
10:04 PM
44
Which of the following sets of numbers are all natural numbers?
Відповідь
(B)
1, 2, 3, 4
45
Which of the following is NOT a property of prime numbers?
Відповідь
(C)
They are all odd numbers.
46
What is the reciprocal of 2/3?
Відповідь
(C)
3/2
47
What is the name for a number that cannot be written as a fraction?
Відповідь
(C)
Irrational number
48
Which of the following numbers is NOT a natural number?
Відповідь
(A)
0
49
Which set of numbers are all integers?
Відповідь
(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?
