Mathematics
Number System
Find the next term in the series: 13, 22, 33, 46, 61, ?
A. 78
B. 76
C. 93
D. 80
Correct Answer: A
The first differences are [9, 11, 13, 15]; their second difference is constant at 2. Continuing the pattern gives 78.
Mathematics
Number System
The sum of 3 consecutive integers is 135. What is the middle integer?
A. 46
B. 45
C. 44
D. 48
Correct Answer: B
The middle integer equals the average: 135 ÷ 3 = 45.
Mathematics
Number System
How is the integer 73 classified?
A. Neither prime nor composite
B. Composite
C. Prime
D. Irrational
Correct Answer: C
73 has exactly two positive divisors, 1 and 73; therefore it is prime.
Mathematics
Number System
Find the next number: 4, 5, 9, 18, 34, ?
A. 50
B. 64
C. 54
D. 59
Correct Answer: D
The increments are consecutive squares: 1, 4, 9, 16; next add 5² = 25. So the answer is 59.
Mathematics
Number System
What is the greatest multiple of 18 that is less than 1418?
A. 1422
B. 1405
C. 1404
D. 1386
Correct Answer: C
1418 ÷ 18 has integer quotient 78; 18 × 78 = 1404.
Mathematics
Number System
A two-digit number is 91. What is the absolute difference between the number and the number formed by reversing its digits?
A. 81
B. 63
C. 72
D. 8
Correct Answer: C
Reversed number = 19. Absolute difference = |91 - 19| = 72.
Mathematics
Number System
Find the next number: 22, 25, 29, 34, 40, ?
A. 47
B. 43
C. 46
D. 48
Correct Answer: A
The differences are 3, 4, 5, 6, increasing by 1. The next difference is 7, so the answer is 47.
Mathematics
Number System
How is the integer 83 classified?
A. Irrational
B. Prime
C. Composite
D. Neither prime nor composite
Correct Answer: B
83 has exactly two positive divisors, 1 and 83; therefore it is prime.
Mathematics
Number System
Find the missing number: 21, 33, 45, ?, 69, 81
A. 45
B. 69
C. 57
D. 81
Correct Answer: C
This is an arithmetic series with common difference 12; the missing term is 57.
Mathematics
Number System
Find the next term: 5, 12, 31, 68, ?
A. 125
B. 54
C. 134
D. 129
Correct Answer: D
Each term is n³ + 4. Thus the next term is 5³ + 4 = 129.
Mathematics
Number System
Classify √6.
A. Prime number
B. Rational
C. Irrational
D. Whole number
Correct Answer: C
6 is not a perfect square, so √6 is irrational.
Mathematics
Number System
What digit x makes the number 376x divisible by 9?
A. 7
B. 3
C. 5
D. 2
Correct Answer: D
A number is divisible by 9 when its digit sum is divisible by 9. Thus 3+7+6+x must be a multiple of 9, giving x = 2.
Mathematics
Number System
What is the greatest multiple of 30 that is less than 846?
A. 841
B. 840
C. 870
D. 810
Correct Answer: B
846 ÷ 30 has integer quotient 28; 30 × 28 = 840.
Mathematics
Number System
How is the integer 70 classified?
A. Neither prime nor composite
B. Prime
C. Composite
D. Irrational
Correct Answer: C
70 = 7 × 10, so it has factors other than 1 and itself and is composite.
Mathematics
Number System
What is the least positive number exactly divisible by 18, 10, and 16?
A. 720
B. 18
C. 730
D. 1440
Correct Answer: A
The required number is LCM(18, 10, 16) = 720.
Mathematics
Number System
Two positive integers have HCF 2 and LCM 70. What is their product?
A. 72
B. 140
C. 70
D. 142
Correct Answer: B
For two positive integers, product = HCF × LCM = 2 × 70 = 140.
Mathematics
Number System
Find the next number: 10, 21, 43, 87, 175, ?
A. 352
B. 351
C. 350
D. 349
Correct Answer: B
Each term is obtained by ×2 + 1. So 175 × 2 + 1 = 351.
Mathematics
Number System
Find the next number in the series: 24, 29, 34, 39, 44, ?
A. 59
B. 54
C. 49
D. 44
Correct Answer: C
The common difference is 5. So the next term is 44 + 5 = 49.
Mathematics
Number System
The sum of 5 consecutive integers is 145. What is the middle integer?
A. 29
B. 28
C. 30
D. 34
Correct Answer: A
The middle integer equals the average: 145 ÷ 5 = 29.
Mathematics
Number System
Find the next term in the series: 17, 28, 43, 62, 85, ?
A. 135
B. 108
C. 116
D. 112
Correct Answer: D
The first differences are [11, 15, 19, 23]; their second difference is constant at 4. Continuing the pattern gives 112.