Number System MCQs 2026

45 questions with detailed answers · 19 from past papers · 5 quiz batches available

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Read each question, think about the answer, then click Show Answer to reveal the correct option and explanation. Load 10 at a time so it stays manageable — perfect for one-topic study sessions on the bus or during a break.

Page 1 of 1Questions 1–10 of 45

Q1Past Paper · PPSC/FPSC/NTSeasy
The smallest prime number is
1. A1
2. B2
3. C3
4. D4
💡 Explanation:
2 is the smallest prime number and the only even prime.
Q2Past Paper · PPSC/FPSC/NTSeasy
The smallest whole number is
1. A0
2. B1
3. C2
4. D-1
💡 Explanation:
Whole numbers start from 0, so the smallest whole number is 0.
Q3easy
The reciprocal of 5 is
1. A5
2. B-5
3. C0
4. D1/5
💡 Explanation:
The reciprocal of a number n is 1/n, so the reciprocal of 5 is 1/5.
Q4easy
The number just before 1000 is
1. A1001
2. B999
3. C998
4. D1000
💡 Explanation:
The number immediately before 1000 is 999.
Q5Past Paper · PPSC/FPSC/NTSeasy
The smallest composite number is
1. A2
2. B4
3. C6
4. D1
💡 Explanation:
4 is the smallest composite number (its factors are 1, 2 and 4).
Q6Past Paper · PPSC/FPSC/NTSeasy
The smallest natural number is
1. A0
2. B2
3. C-1
4. D1
💡 Explanation:
Natural numbers start from 1, so the smallest natural number is 1.
Q7Past Paper · PPSC/FPSC/NTSeasy
The only even prime number is
1. A4
2. B6
3. C2
4. D0
💡 Explanation:
2 is the only even number that is prime.
Q8easy
How many even numbers lie between 1 and 10 (exclusive)
1. A3
2. B5
3. C4
4. D6
💡 Explanation:
The even numbers between 1 and 10 are 2, 4, 6 and 8, giving 4 numbers.
Q9easy
The value of 1 + 3 + 5 + 7 is
1. A12
2. B15
3. C16
4. D18
💡 Explanation:
1+3+5+7 = 16, which is also 4² (sum of first 4 odd numbers).
Q10Past Paper · PPSC/FPSC/NTSmedium
The sum of the first n odd numbers is
1. A2n
2. Bn squared
3. Cn(n+1)/2
4. Dn
💡 Explanation:
The sum of the first n odd numbers equals n², e.g. 1+3+5 = 9 = 3².
Q11easy
Which of the following is a prime number
1. A23
2. B15
3. C21
4. D33
💡 Explanation:
23 has only two factors, 1 and 23, so it is prime.
Q12easy
Which of the following is a composite number
1. A2
2. B3
3. C5
4. D9
💡 Explanation:
9 has factors 1, 3 and 9, so it is composite; the others are prime.
Q13easy
The predecessor of 100 is
1. A101
2. B100
3. C99
4. D98
💡 Explanation:
The predecessor is the previous number, so 100−1 = 99.
Q14easy
The successor of 99 is
1. A98
2. B100
3. C99
4. D101
💡 Explanation:
The successor of a number is the next number, so 99+1 = 100.
Q15easy
The smallest 3-digit number is
1. A100
2. B111
3. C99
4. D101
💡 Explanation:
The smallest three-digit number is 100.
Q16easy
The largest 3-digit number is
1. A100
2. B900
3. C998
4. D999
💡 Explanation:
The largest three-digit number is 999.
Q17Past Paper · PPSC/FPSC/NTSmedium
The HCF of two co-prime numbers is
1. A0
2. B2
3. C1
4. DTheir product
💡 Explanation:
Co-prime numbers share no common factor other than 1, so their HCF is 1.
Q18Past Paper · PPSC/FPSC/NTSeasy
How many factors does a prime number have
1. A2
2. B1
3. C3
4. D0
💡 Explanation:
A prime number has exactly two factors: 1 and itself.
Q19easy
The face value of 7 in the number 4750 is
1. A700
2. B70
3. C750
4. D7
💡 Explanation:
The face value of a digit is the digit itself, so it is 7.
Q20easy
The place value of 7 in the number 4750 is
1. A7
2. B700
3. C70
4. D750
💡 Explanation:
7 is in the hundreds place, so its place value is 7×100 = 700.
Q21easy
The sum of two even numbers is always
1. AOdd
2. BPrime
3. CEven
4. DZero
💡 Explanation:
Even + even always gives an even number, e.g. 4+6 = 10.
Q22easy
The product of two odd numbers is always
1. AOdd
2. BEven
3. CZero
4. DPrime
💡 Explanation:
Odd × odd always gives an odd number, e.g. 3×5 = 15.
Q23Past Paper · PPSC/FPSC/NTSmedium
A number that can be written in the form p/q (q ≠ 0) is called a/an
1. AIrrational number
2. BPrime number
3. CNatural number
4. DRational number
💡 Explanation:
A rational number can be expressed as a ratio p/q where q ≠ 0.
Q24Past Paper · PPSC/FPSC/NTSmedium
The number √2 is an example of a/an
1. ARational number
2. BIrrational number
3. CNatural number
4. DWhole number
💡 Explanation:
√2 cannot be written as a simple fraction, so it is irrational.
Q25Past Paper · PPSC/FPSC/NTSeasy
The value of √144 is
1. A12
2. B14
3. C16
4. D11
💡 Explanation:
√144 = 12 because 12×12 = 144.
Q26easy
The square of 12 is
1. A24
2. B121
3. C169
4. D144
💡 Explanation:
12² = 12×12 = 144.
Q27easy
The value of 2 raised to the power 5 (2⁵) is
1. A10
2. B16
3. C32
4. D64
💡 Explanation:
2⁵ = 2×2×2×2×2 = 32.
Q28Past Paper · PPSC/FPSC/NTSeasy
The value of 5 cubed (5³) is
1. A15
2. B125
3. C25
4. D625
💡 Explanation:
5³ = 5×5×5 = 125.
Q29easy
Which of the following is a whole number but not a natural number
1. A0
2. B1
3. C2
4. D5
💡 Explanation:
0 is a whole number but not a natural number.
Q30Past Paper · PPSC/FPSC/NTSeasy
The product of any number and 0 is
1. AThe number itself
2. B1
3. CUndefined
4. D0
💡 Explanation:
Multiplying any number by 0 gives 0.
Q31Past Paper · PPSC/FPSC/NTSmedium
The largest 2-digit prime number is
1. A91
2. B93
3. C97
4. D99
💡 Explanation:
97 is prime and is the largest prime below 100.
Q32medium
Which of the following numbers is divisible by 6
1. A112
2. B114
3. C115
4. D119
💡 Explanation:
114 is even and 1+1+4 = 6 is divisible by 3, so it is divisible by 6.
Q33medium
Which of the following numbers is divisible by 4
1. A116
2. B114
3. C118
4. D122
💡 Explanation:
A number is divisible by 4 if its last two digits are; 16 is divisible by 4, so 116 is.
Q34Past Paper · PPSC/FPSC/NTSmedium
The number 0 is
1. AAn odd number
2. BA prime number
3. CNeither even nor odd
4. DAn even number
💡 Explanation:
0 is divisible by 2, so it is considered an even number.
Q35easy
Which of the following numbers is divisible by 10
1. A105
2. B315
3. C220
4. D412
💡 Explanation:
A number ending in 0 is divisible by 10, so 220 qualifies.
Q36medium
Which of the following numbers is divisible by 9
1. A234
2. B235
3. C236
4. D238
💡 Explanation:
2+3+4 = 9, which is divisible by 9, so 234 is divisible by 9.
Q37easy
Which of the following numbers is divisible by 5
1. A52
2. B58
3. C61
4. D55
💡 Explanation:
A number ending in 0 or 5 is divisible by 5, so 55 qualifies.
Q38easy
Which of the following numbers is divisible by 3
1. A121
2. B123
3. C124
4. D125
💡 Explanation:
1+2+3 = 6, which is divisible by 3, so 123 is divisible by 3.
Q39easy
Which of the following is an odd number
1. A24
2. B36
3. C47
4. D50
💡 Explanation:
47 is not divisible by 2, so it is an odd number.
Q40easy
A number divisible by 2 is called a/an
1. AEven number
2. BOdd number
3. CPrime number
4. DComposite number
💡 Explanation:
Any number exactly divisible by 2 is an even number.
Q41easy
The sum of the first 5 natural numbers is
1. A10
2. B20
3. C25
4. D15
💡 Explanation:
Sum = 1+2+3+4+5 = 15, or 5×6/2 = 15.
Q42Past Paper · PPSC/FPSC/NTSeasy
The sum of the first 10 natural numbers is
1. A45
2. B55
3. C50
4. D60
💡 Explanation:
Sum = n(n+1)/2 = 10×11/2 = 55.
Q43Past Paper · PPSC/FPSC/NTSeasy
The number 1 is
1. APrime
2. BComposite
3. CNeither prime nor composite
4. DAn even prime
💡 Explanation:
1 is neither prime nor composite by definition.
Q44Past Paper · PPSC/FPSC/NTSmedium
How many prime numbers are there between 1 and 20
1. A8
2. B9
3. C10
4. D7
💡 Explanation:
The primes up to 20 are 2,3,5,7,11,13,17,19 — a total of 8.
Q45Past Paper · PPSC/FPSC/NTSeasy
How many prime numbers are there between 1 and 10
1. A2
2. B3
3. C5
4. D4
💡 Explanation:
The primes between 1 and 10 are 2, 3, 5 and 7, giving 4 primes.

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Number System MCQs 2026

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