Mathematics
Number System
Find the next term: 13, 20, 33, 53, 86, 139, ?
A. 225
B. 172
C. 278
D. 258
Correct Answer: A
Each term is the sum of the previous two. Therefore 86 + 139 = 225.
Mathematics
Number System
Find the next number: 6, 16, 36, 76, 156, ?
A. 320
B. 316
C. 314
D. 312
Correct Answer: B
Each term is obtained by ×2 + 4. So 156 × 2 + 4 = 316.
Mathematics
Number System
How many positive divisors does 2025 have?
A. 8
B. 14
C. 17
D. 15
Correct Answer: D
2025 = 3^4 × 5^2. Number of divisors = (4+1)(2+1) = 15.
Mathematics
Number System
The sum of 4 consecutive integers is 238. What is the smallest integer?
A. 59
B. 62
C. 58
D. 57
Correct Answer: C
Let the integers be n, n+1, ..., n+3. Their sum is 238; solving gives n = 58.
Mathematics
Number System
What is the units digit of 57^88?
A. 1
B. 3
C. 7
D. 5
Correct Answer: A
Units digits repeat cyclically; applying the cycle for base 57 gives units digit 1.
Mathematics
Number System
Find the LCM of 5 and 17.
A. 93
B. 85
C. 17
D. 86
Correct Answer: B
LCM = (5 × 17) ÷ HCF(5,17) = 85.
Mathematics
Number System
What digit x makes the number 522x divisible by 9?
A. 1
B. 0
C. 3
D. 5
Correct Answer: B
A number is divisible by 9 when its digit sum is divisible by 9. Thus 5+2+2+x must be a multiple of 9, giving x = 0.
Mathematics
Number System
Find the next number: 36, 42, 50, 60, 72, ?
A. 86
B. 84
C. 88
D. 78
Correct Answer: A
The differences are 6, 8, 10, 12, increasing by 2. The next difference is 14, so the answer is 86.
Mathematics
Number System
Find the next number: 4, 15, 48, 147, 444, ?
A. 1338
B. 1332
C. 1468
D. 1335
Correct Answer: D
Each term is obtained by ×3 + 3. So 444 × 3 + 3 = 1335.
Mathematics
Number System
Find the missing number: 86, 104, 122, 140, ?, 176
A. 140
B. 194
C. 158
D. 176
Correct Answer: C
This is an arithmetic series with common difference 18; the missing term is 158.
Mathematics
Number System
Find the next number: 38, 40, 46, 56, 70, ?
A. 72
B. 84
C. 92
D. 88
Correct Answer: D
The differences are 2, 6, 10, 14, increasing by 4. The next difference is 18, so the answer is 88.
Mathematics
Number System
How is the integer 41 classified?
A. Irrational
B. Composite
C. Neither prime nor composite
D. Prime
Correct Answer: D
41 has exactly two positive divisors, 1 and 41; therefore it is prime.
Mathematics
Number System
Classify 3/17.
A. Prime number
B. Whole number
C. Irrational
D. Rational
Correct Answer: D
3/17 is a ratio of two integers with a non-zero denominator, so it is rational.
Mathematics
Number System
Find the next number: 14, 16, 19, 24, 31, ?
A. 44
B. 49
C. 31
D. 42
Correct Answer: D
Successive prime numbers are added: 2, 3, 5, 7, 11. Add 11 next, giving 42.
Mathematics
Number System
Two positive integers have HCF 3 and LCM 120. What is their product?
A. 360
B. 123
C. 363
D. 120
Correct Answer: A
For two positive integers, product = HCF × LCM = 3 × 120 = 360.
Mathematics
Number System
What is the remainder when 2135 is divided by 12?
A. 2
B. 0
C. 11
D. 1
Correct Answer: C
2135 = 12 × 177 + 11; therefore the remainder is 11.
Mathematics
Number System
Find the next number: 17, 18, 22, 31, 47, ?
A. 72
B. 77
C. 63
D. 67
Correct Answer: A
The increments are consecutive squares: 1, 4, 9, 16; next add 5² = 25. So the answer is 72.
Mathematics
Number System
Find the next number: 10, 16, 26, 40, 58, ?
A. 80
B. 84
C. 64
D. 76
Correct Answer: A
The differences are 6, 10, 14, 18, increasing by 4. The next difference is 22, so the answer is 80.
Mathematics
Number System
Find the next number in the series: 22, 28, 34, 40, 46, ?
A. 58
B. 64
C. 52
D. 46
Correct Answer: C
The common difference is 6. So the next term is 46 + 6 = 52.
Mathematics
Number System
Find the next number: 11, 14, 19, 26, 37, ?
A. 52
B. 61
C. 37
D. 50
Correct Answer: D
Successive prime numbers are added: 3, 5, 7, 11, 13. Add 13 next, giving 50.