Odd One Out Worksheet for Maths Olympiad
How to solve it (Find the shared rule): Check whether all the numbers are odd or all even — if so, look deeper. Try the tables 3, 4, 5, 6, 7, 8 and 9: which one has three of the numbers in it? The number that is not in that table is the odd one out.
NameDateTime takenScore ___ / 40
- 1.Which is the odd one out: 24, 16, 48, 46? (a) 24 (b) 16 (c) 48 (d) 46
- 2.Which is the odd one out: 16, 24, 48, 44? (a) 16 (b) 24 (c) 48 (d) 44
- 3.Which is the odd one out: 81, 63, 45, 35? (a) 81 (b) 63 (c) 45 (d) 35
- 4.Which is the odd one out: 35, 81, 45, 27? (a) 35 (b) 81 (c) 45 (d) 27
- 5.Which is the odd one out: 46, 12, 60, 30? (a) 46 (b) 12 (c) 60 (d) 30
- 6.Which is the odd one out: 36, 44, 66, 54? (a) 36 (b) 44 (c) 66 (d) 54
- 7.Which is the odd one out: 50, 80, 96, 24? (a) 50 (b) 80 (c) 96 (d) 24
- 8.Which is the odd one out: 30, 20, 36, 54? (a) 30 (b) 20 (c) 36 (d) 54
- 9.Which is the odd one out: 16, 20, 14, 40? (a) 16 (b) 20 (c) 14 (d) 40
- 10.Which is the odd one out: 16, 84, 56, 48? (a) 16 (b) 84 (c) 56 (d) 48
- 11.Which is the odd one out: 12, 34, 24, 16? (a) 12 (b) 34 (c) 24 (d) 16
- 12.Which is the odd one out: 66, 16, 32, 96? (a) 66 (b) 16 (c) 32 (d) 96
- 13.Which is the odd one out: 20, 34, 32, 40? (a) 20 (b) 34 (c) 32 (d) 40
- 14.Which is the odd one out: 16, 32, 48, 54? (a) 16 (b) 32 (c) 48 (d) 54
- 15.Which is the odd one out: 54, 24, 34, 72? (a) 54 (b) 24 (c) 34 (d) 72
- 16.Which is the odd one out: 24, 96, 64, 20? (a) 24 (b) 96 (c) 64 (d) 20
- 17.Which is the odd one out: 70, 80, 24, 96? (a) 70 (b) 80 (c) 24 (d) 96
- 18.Which is the odd one out: 45, 27, 81, 85? (a) 45 (b) 27 (c) 81 (d) 85
- 19.Which is the odd one out: 60, 46, 12, 30? (a) 60 (b) 46 (c) 12 (d) 30
- 20.Which is the odd one out: 81, 65, 45, 27? (a) 81 (b) 65 (c) 45 (d) 27
- 21.Which is the odd one out: 10, 24, 12, 48? (a) 10 (b) 24 (c) 12 (d) 48
- 22.Which is the odd one out: 96, 32, 66, 16? (a) 96 (b) 32 (c) 66 (d) 16
- 23.Which is the odd one out: 42, 48, 16, 32? (a) 42 (b) 48 (c) 16 (d) 32
- 24.Which is the odd one out: 30, 96, 80, 16? (a) 30 (b) 96 (c) 80 (d) 16
- 25.Which is the odd one out: 32, 12, 22, 24? (a) 32 (b) 12 (c) 22 (d) 24
- 26.Which is the odd one out: 28, 56, 16, 32? (a) 28 (b) 56 (c) 16 (d) 32
- 27.Which is the odd one out: 32, 48, 96, 38? (a) 32 (b) 48 (c) 96 (d) 38
- 28.Which is the odd one out: 42, 32, 16, 28? (a) 42 (b) 32 (c) 16 (d) 28
- 29.Which is the odd one out: 84, 80, 40, 96? (a) 84 (b) 80 (c) 40 (d) 96
- 30.Which is the odd one out: 54, 18, 72, 64? (a) 54 (b) 18 (c) 72 (d) 64
- 31.Which is the odd one out: 65, 81, 45, 27? (a) 65 (b) 81 (c) 45 (d) 27
- 32.Which is the odd one out: 33, 81, 27, 99? (a) 33 (b) 81 (c) 27 (d) 99
- 33.Which is the odd one out: 24, 72, 28, 36? (a) 24 (b) 72 (c) 28 (d) 36
- 34.Which is the odd one out: 62, 48, 24, 12? (a) 62 (b) 48 (c) 24 (d) 12
- 35.Which is the odd one out: 32, 24, 48, 34? (a) 32 (b) 24 (c) 48 (d) 34
- 36.Which is the odd one out: 27, 35, 45, 81? (a) 27 (b) 35 (c) 45 (d) 81
- 37.Which is the odd one out: 66, 48, 80, 40? (a) 66 (b) 48 (c) 80 (d) 40
- 38.Which is the odd one out: 27, 81, 45, 85? (a) 27 (b) 81 (c) 45 (d) 85
- 39.Which is the odd one out: 32, 12, 24, 38? (a) 32 (b) 12 (c) 24 (d) 38
- 40.Which is the odd one out: 63, 45, 35, 27? (a) 63 (b) 45 (c) 35 (d) 27
Answer key
- 46
- 44
- 35
- 35
- 46
- 44
- 50
- 20
- 14
- 84
- 34
- 66
- 34
- 54
- 34
- 20
- 70
- 85
- 46
- 65
- 10
- 66
- 42
- 30
- 22
- 28
- 38
- 42
- 84
- 64
- 65
- 33
- 28
- 62
- 34
- 35
- 66
- 85
- 38
- 35
Free maths olympiad lessons, practice and worksheets at talentjr.in/maths-olympiad