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