CSS - PMS - CCE - PCS - Mathematics
Number System
What digit x makes the number 514x divisible by 9?
A. 3
B. 1
C. 9
D. 8
Correct Answer: D
A number is divisible by 9 when its digit sum is divisible by 9. Thus 5+1+4+x must be a multiple of 9, giving x = 8.
CSS - PMS - CCE - PCS - Mathematics
Number System
Find the next number: 4, 8, 24, 96, 480, ?
A. 2880
B. 2886
C. 2400
D. 480
Correct Answer: A
The multipliers are ×2, ×3, ×4, ×5; the next multiplier is ×6. Thus 480 × 6 = 2880.
CSS - PMS - CCE - PCS - Mathematics
Number System
What is the units digit of 48^91?
A. 8
B. 2
C. 4
D. 6
Correct Answer: B
Units digits repeat cyclically; applying the cycle for base 48 gives units digit 2.
CSS - PMS - CCE - PCS - Mathematics
Number System
The sum of 3 consecutive integers is 162. What is the middle integer?
A. 53
B. 57
C. 55
D. 54
Correct Answer: D
The middle integer equals the average: 162 ÷ 3 = 54.
CSS - PMS - CCE - PCS - Mathematics
Number System
What is the greatest positive integer that can divide both 599 and 575 leaving the same remainder?
A. 23
B. 12
C. 24
D. 25
Correct Answer: C
If both numbers leave the same remainder, their difference must be divisible by the divisor. Their difference is 599-575 = 24; the greatest possible divisor is 24.
CSS - PMS - CCE - PCS - Mathematics
Number System
Find the next number in the series: 4, 16, 64, 256, 1024, ?
A. 4100
B. 1024
C. 4096
D. 1028
Correct Answer: C
Each term is multiplied by 4. Therefore 1024 × 4 = 4096.
CSS - PMS - CCE - PCS - Mathematics
Number System
What is the least positive number exactly divisible by 9, 7, and 17?
A. 1071
B. 17
C. 2142
D. 1078
Correct Answer: A
The required number is LCM(9, 7, 17) = 1071.
CSS - PMS - CCE - PCS - Mathematics
Number System
Two positive integers have HCF 5 and LCM 715. What is their product?
A. 3580
B. 720
C. 3575
D. 715
Correct Answer: C
For two positive integers, product = HCF × LCM = 5 × 715 = 3575.
CSS - PMS - CCE - PCS - Mathematics
Number System
Find the missing number: 75, 89, 103, ?, 131, 145
A. 117
B. 103
C. 131
D. 145
Correct Answer: A
This is an arithmetic series with common difference 14; the missing term is 117.
CSS - PMS - CCE - PCS - Mathematics
Number System
Find the next number in the series: 70, 76, 82, 88, 94, ?
A. 112
B. 100
C. 106
D. 94
Correct Answer: B
The common difference is 6. So the next term is 94 + 6 = 100.
CSS - PMS - CCE - PCS - Mathematics
Number System
Find the LCM of 24 and 21.
A. 24
B. 504
C. 168
D. 171
Correct Answer: C
LCM = (24 × 21) ÷ HCF(24,21) = 168.
CSS - PMS - CCE - PCS - Mathematics
Number System
Find the next number: 5, 7, 10, 15, 22, ?
A. 35
B. 22
C. 33
D. 40
Correct Answer: C
Successive prime numbers are added: 2, 3, 5, 7, 11. Add 11 next, giving 33.
CSS - PMS - CCE - PCS - Mathematics
Number System
Find the next term: 13, 22, 35, 57, 92, 149, ?
A. 276
B. 298
C. 184
D. 241
Correct Answer: D
Each term is the sum of the previous two. Therefore 92 + 149 = 241.
CSS - PMS - CCE - PCS - Mathematics
Number System
A two-digit number is 49. What is the absolute difference between the number and the number formed by reversing its digits?
A. 54
B. 36
C. 45
D. 5
Correct Answer: C
Reversed number = 94. Absolute difference = |49 - 94| = 45.
CSS - PMS - CCE - PCS - Mathematics
Number System
Find the next number: 30, 39, 55, 80, 116, ?
A. 152
B. 172
C. 165
D. 158
Correct Answer: C
The increments are consecutive squares: 9, 16, 25, 36; next add 7² = 49. So the answer is 165.
CSS - PMS - CCE - PCS - Mathematics
Number System
Find the next number in the series: 3, 15, 75, 375, 1875, ?
A. 1880
B. 1875
C. 9380
D. 9375
Correct Answer: D
Each term is multiplied by 5. Therefore 1875 × 5 = 9375.
CSS - PMS - CCE - PCS - Mathematics
Number System
Find the next number: 7, 8, 11, 16, 23, ?
A. 32
B. 24
C. 34
D. 30
Correct Answer: A
The differences are 1, 3, 5, 7, increasing by 2. The next difference is 9, so the answer is 32.
CSS - PMS - CCE - PCS - Mathematics
Number System
What least number must be subtracted from 3243 so that the result is exactly divisible by 12?
A. 2
B. 15
C. 9
D. 3
Correct Answer: D
The remainder is 3; subtracting the remainder makes the number divisible by 12.
CSS - PMS - CCE - PCS - Mathematics
Number System
The sum of 5 consecutive integers is 40. What is the middle integer?
A. 8
B. 7
C. 13
D. 9
Correct Answer: A
The middle integer equals the average: 40 ÷ 5 = 8.
CSS - PMS - CCE - PCS - Mathematics
Number System
Find the next number in the alternating series: 8, 22, 16, 19, 24, 16, ?
A. 40
B. 24
C. 13
D. 32
Correct Answer: D
Odd-position terms are 8, 16, 24, ... with difference 8. Hence the next odd-position term is 32.