Mathematics
Number System
Find the next term in the series: 12, 23, 40, 63, 92, ?
A. 121
B. 127
C. 133
D. 156
Correct Answer: B
The first differences are [11, 17, 23, 29]; their second difference is constant at 6. Continuing the pattern gives 127.
Mathematics
Number System
A two-digit number is 73. What is the absolute difference between the number and the number formed by reversing its digits?
A. 4
B. 27
C. 45
D. 36
Correct Answer: D
Reversed number = 37. Absolute difference = |73 - 37| = 36.
Mathematics
Number System
How many integers from 25 to 238, inclusive, are divisible by 15?
A. 13
B. 15
C. 14
D. 16
Correct Answer: C
Count = ⌊238/15⌋ - ⌊(25-1)/15⌋ = 15 - 1 = 14.
Mathematics
Number System
What is the least positive number exactly divisible by 4, 5, and 12?
A. 12
B. 120
C. 60
D. 64
Correct Answer: C
The required number is LCM(4, 5, 12) = 60.
Mathematics
Number System
What is the greatest positive integer that can divide both 329 and 286 leaving the same remainder?
A. 42
B. 21
C. 43
D. 44
Correct Answer: C
If both numbers leave the same remainder, their difference must be divisible by the divisor. Their difference is 329-286 = 43; the greatest possible divisor is 43.
Mathematics
Number System
Find the HCF (GCD) of 88 and 64.
A. 8
B. 9
C. 4
D. 16
Correct Answer: A
The greatest common divisor of 88 and 64 is 8.
Mathematics
Number System
Find the next term: 30, 44, 36, 50, 42, 56, ?
A. 34
B. 56
C. 48
D. 70
Correct Answer: C
The operations alternate +14, -8. After the last +14, subtract 8: 56 - 8 = 48.
Mathematics
Number System
Find the next number in the series: 1, 3, 9, 27, 81, ?
A. 81
B. 246
C. 84
D. 243
Correct Answer: D
Each term is multiplied by 3. Therefore 81 × 3 = 243.
Mathematics
Number System
Find the next number in the series: 28, 45, 62, 79, 96, ?
A. 96
B. 113
C. 130
D. 147
Correct Answer: B
The common difference is 17. So the next term is 96 + 17 = 113.
Mathematics
Number System
How many trailing zeros are there in 83! ?
A. 8
B. 19
C. 18
D. 20
Correct Answer: B
Trailing zeros = ⌊83/5⌋ + ⌊83/25⌋ + ... = 16 + 3 = 19.
Mathematics
Number System
How many integers from 50 to 431, inclusive, are divisible by 4?
A. 95
B. 94
C. 107
D. 96
Correct Answer: A
Count = ⌊431/4⌋ - ⌊(50-1)/4⌋ = 107 - 12 = 95.
Mathematics
Number System
Two positive integers have HCF 12 and LCM 624. What is their product?
A. 636
B. 624
C. 7488
D. 7500
Correct Answer: C
For two positive integers, product = HCF × LCM = 12 × 624 = 7488.
Mathematics
Number System
Two positive integers have HCF 13 and LCM 1170. What is their product?
A. 1183
B. 15223
C. 1170
D. 15210
Correct Answer: D
For two positive integers, product = HCF × LCM = 13 × 1170 = 15210.
Mathematics
Number System
Find the next number: 6, 7, 9, 12, 16, ?
A. 17
B. 21
C. 20
D. 22
Correct Answer: B
The differences are 1, 2, 3, 4, increasing by 1. The next difference is 5, so the answer is 21.
Mathematics
Number System
Two positive integers have HCF 10 and LCM 2100. What is their product?
A. 2100
B. 21010
C. 21000
D. 2110
Correct Answer: C
For two positive integers, product = HCF × LCM = 10 × 2100 = 21000.
Mathematics
Number System
Find the next term: 10, 13, 18, 25, 34, ?
A. 45
B. 46
C. 57
D. 33
Correct Answer: A
The terms follow 1n² + 9 for consecutive n. For n = 6, the term is 1×6² + 9 = 45.
Mathematics
Number System
Find the next term: 7, 16, 23, 39, 62, 101, ?
A. 163
B. 186
C. 124
D. 202
Correct Answer: A
Each term is the sum of the previous two. Therefore 62 + 101 = 163.
Mathematics
Number System
A two-digit number is 72. What is the absolute difference between the number and the number formed by reversing its digits?
A. 5
B. 36
C. 45
D. 54
Correct Answer: C
Reversed number = 27. Absolute difference = |72 - 27| = 45.
Mathematics
Number System
What least number must be added to 626 so that the result is exactly divisible by 24?
A. 2
B. 22
C. 24
D. 46
Correct Answer: B
626 leaves remainder 2 on division by 24. Add 24 - 2 = 22.
Mathematics
Number System
Find the next term: 25, 35, 27, 37, 29, 39, ?
A. 31
B. 21
C. 39
D. 49
Correct Answer: A
The operations alternate +10, -8. After the last +10, subtract 8: 39 - 8 = 31.