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

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