Patterns with Twin Primes

1) What pattern do twin primes always share?

One is even, one is odd

Both are odd

Both are even

Both are multiples of 5

Except for (3,5), all twin primes are odd.

Explanation

Except for (3,5), all twin primes are odd.

2) Which twin primes are directly after 10?

11 and 12

11 and 13

12 and 14

13 and 15

They are the next valid twin primes after 10.

Explanation

They are the next valid twin primes after 10.

3) Which pair is part of the pattern of twin primes?

21 and 23

23 and 25

29 and 31

25 and 27

Both are primes and differ by 2.

Explanation

Both are primes and differ by 2.

4) Which number has no twin prime pair?

2

3

5

7

2 is the only even prime and cannot form a twin pair.

Explanation

2 is the only even prime and cannot form a twin pair.

5) Twin primes are part of which larger group?

Composite numbers

Even numbers

Prime numbers

Factors of 100

All twin primes are primes by definition.

Explanation

All twin primes are primes by definition.

6) Which prime pair is closest to 100?

97 and 99

101 and 103

103 and 105

99 and 101

These are the nearest twin primes to 100.

Explanation

These are the nearest twin primes to 100.

7) Which is the missing number in the twin prime pair: (71, __)?

72

73

74

75

71 and 73 are twin primes.

Explanation

71 and 73 are twin primes.

8) Which of these is the correct set of twin primes?

{15, 17}

{17, 19}

{21, 23}

{19, 21}

Both are prime and differ by 2.

Explanation

Both are prime and differ by 2.

9) What is always true about twin primes greater than 3?

One is divisible by 3

Both are of the form 6k ± 1 (for some integer k)

One is divisible by 5

Both are even

This is a number theory fact: all primes > 3 fit 6k±1, and twin primes appear as such pairs.

Explanation

This is a number theory fact: all primes > 3 fit 6k±1, and twin primes appear as such pairs.

10) Which of these twin primes is under 20?

19 and 21

15 and 17

17 and 19

21 and 23

This is the only twin prime pair listed below 20.

Explanation

This is the only twin prime pair listed below 20.

11) Which twin prime pair is between 40 and 50?

41 and 43

45 and 47

47 and 49

Both primes are within the range and differ by 2.

Explanation

Both primes are within the range and differ by 2.

12) Which pair of primes is separated by 6?

29 and 31

31 and 37

17 and 19

23 and 27

These are prime but not twin primes since the difference is 6.

Explanation

These are prime but not twin primes since the difference is 6.

13) Which twin prime set comes before 20?

11 and 13

13 and 15

15 and 17

19 and 21

These appear before 17 & 19, the set closest to 20.

Explanation

These appear before 17 & 19, the set closest to 20.

14) Which number is not part of a twin prime pair?

29

31

41

47

47 is prime but neither 45 nor 49 is prime, so no twin.

Explanation

47 is prime but neither 45 nor 49 is prime, so no twin.

15) Which twin prime set is just above 50?

50 and 52

51 and 53

53 and 55

59 and 61

This pair comes right after 50.

Explanation

This pair comes right after 50.

16) Which number is in two different twin prime sets?

None – primes can only be in one twin prime pair

29

41

59

A prime can only belong to one twin pair.

Explanation

A prime can only belong to one twin pair.

17) Which twin primes are directly after 70?

71 and 73

73 and 75

75 and 77

77 and 79

Both primes directly after 70.

Explanation

Both primes directly after 70.

18) Which twin primes are between 80 and 90?

81 and 83

83 and 85

85 and 87

There are no twin primes between 80 and 90

None of the numbers form valid twin pairs.

Explanation

None of the numbers form valid twin pairs.

19) Which twin primes are closest to 120?

119 and 121

121 and 123

127 and 129

129 and 131

They are the nearest valid pair to 120.

Explanation

They are the nearest valid pair to 120.

20) Which rule helps identify twin primes?

Even + Even = Odd

Odd Prime + 2 = Another Odd Prime

Prime × Prime = Composite

Prime – Prime = Prime

This is the working rule for finding twin primes.

Explanation

This is the working rule for finding twin primes.