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

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