Mathematics
Number System
Find the next number: 9, 12, 17, 24, 35, ?
A. 48
B. 35
C. 59
D. 50
Correct Answer: A
Successive prime numbers are added: 3, 5, 7, 11, 13. Add 13 next, giving 48.
Mathematics
Number System
Find the next number in the alternating series: 13, 49, 16, 52, 19, 55, ?
A. 25
B. 58
C. 19
D. 22
Correct Answer: D
Odd-position terms are 13, 16, 19, ... with difference 3. Hence the next odd-position term is 22.
Mathematics
Number System
How many integers from 29 to 276, inclusive, are divisible by 13?
A. 19
B. 21
C. 20
D. 18
Correct Answer: A
Count = ⌊276/13⌋ - ⌊(29-1)/13⌋ = 21 - 2 = 19.
Mathematics
Number System
Find the next number: 1, 5, 13, 29, 61, ?
A. 125
B. 122
C. 123
D. 128
Correct Answer: A
Each term is obtained by ×2 + 3. So 61 × 2 + 3 = 125.
Mathematics
Number System
What is the least positive number exactly divisible by 8, 10, and 9?
A. 360
B. 368
C. 10
D. 720
Correct Answer: A
The required number is LCM(8, 10, 9) = 360.
Mathematics
Number System
Find the HCF (GCD) of 55 and 20.
A. 6
B. 10
C. 5
D. 2
Correct Answer: C
The greatest common divisor of 55 and 20 is 5.
Mathematics
Number System
Find the next number: 16, 18, 21, 25, 30, ?
A. 32
B. 36
C. 35
D. 37
Correct Answer: B
The differences are 2, 3, 4, 5, increasing by 1. The next difference is 6, so the answer is 36.
Mathematics
Number System
Find the next term: 6, 24, 30, 54, 84, 138, ?
A. 252
B. 276
C. 222
D. 168
Correct Answer: C
Each term is the sum of the previous two. Therefore 84 + 138 = 222.
Mathematics
Number System
Find the next number: 13, 20, 31, 44, 61, ?
A. 61
B. 82
C. 97
D. 80
Correct Answer: D
Successive prime numbers are added: 7, 11, 13, 17, 19. Add 19 next, giving 80.
Mathematics
Number System
What is the units digit of 33^98?
A. 1
B. 3
C. 9
D. 5
Correct Answer: C
Units digits repeat cyclically; applying the cycle for base 33 gives units digit 9.
Mathematics
Number System
How many positive divisors does 20 have?
A. 8
B. 5
C. 6
D. 7
Correct Answer: C
20 = 2^2 × 5^1. Number of divisors = (2+1)(1+1) = 6.
Mathematics
Number System
Find the next number: 15, 31, 56, 92, 141, ?
A. 190
B. 205
C. 213
D. 197
Correct Answer: B
The increments are consecutive squares: 16, 25, 36, 49; next add 8² = 64. So the answer is 205.
Mathematics
Number System
The sum of 5 consecutive integers is 85. What is the middle integer?
A. 22
B. 18
C. 16
D. 17
Correct Answer: D
The middle integer equals the average: 85 ÷ 5 = 17.
Mathematics
Number System
Find the next number: 1, 5, 17, 53, 161, ?
A. 482
B. 485
C. 487
D. 483
Correct Answer: B
Each term is obtained by ×3 + 2. So 161 × 3 + 2 = 485.
Mathematics
Number System
What least number must be subtracted from 1508 so that the result is exactly divisible by 23?
A. 36
B. 12
C. 10
D. 13
Correct Answer: D
The remainder is 13; subtracting the remainder makes the number divisible by 23.
Mathematics
Number System
Find the next number in the series: 1, 4, 16, 64, 256, ?
A. 260
B. 1024
C. 1028
D. 256
Correct Answer: B
Each term is multiplied by 4. Therefore 256 × 4 = 1024.
Mathematics
Number System
Find the next number in the series: 21, 27, 33, 39, 45, ?
A. 57
B. 45
C. 51
D. 63
Correct Answer: C
The common difference is 6. So the next term is 45 + 6 = 51.
Mathematics
Number System
Find the next term: 6, 9, 14, 21, 30, ?
A. 41
B. 42
C. 53
D. 29
Correct Answer: A
The terms follow 1n² + 5 for consecutive n. For n = 6, the term is 1×6² + 5 = 41.
Mathematics
Number System
Find the LCM of 29 and 29.
A. 58
B. 31
C. 841
D. 29
Correct Answer: D
LCM = (29 × 29) ÷ HCF(29,29) = 29.
Mathematics
Number System
Find the next term in the series: 22, 38, 58, 82, 110, ?
A. 170
B. 146
C. 142
D. 138
Correct Answer: C
The first differences are [16, 20, 24, 28]; their second difference is constant at 4. Continuing the pattern gives 142.