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: 10, 48, 24, 12? (a) 10 (b) 48 (c) 24 (d) 12
- 2.Which is the odd one out: 12, 24, 34, 16? (a) 12 (b) 24 (c) 34 (d) 16
- 3.Which is the odd one out: 81, 27, 35, 63? (a) 81 (b) 27 (c) 35 (d) 63
- 4.Which is the odd one out: 82, 16, 32, 64? (a) 82 (b) 16 (c) 32 (d) 64
- 5.Which is the odd one out: 55, 35, 49, 77? (a) 55 (b) 35 (c) 49 (d) 77
- 6.Which is the odd one out: 20, 30, 48, 16? (a) 20 (b) 30 (c) 48 (d) 16
- 7.Which is the odd one out: 64, 96, 48, 70? (a) 64 (b) 96 (c) 48 (d) 70
- 8.Which is the odd one out: 40, 78, 32, 80? (a) 40 (b) 78 (c) 32 (d) 80
- 9.Which is the odd one out: 27, 35, 45, 63? (a) 27 (b) 35 (c) 45 (d) 63
- 10.Which is the odd one out: 12, 48, 44, 24? (a) 12 (b) 48 (c) 44 (d) 24
- 11.Which is the odd one out: 48, 58, 16, 96? (a) 48 (b) 58 (c) 16 (d) 96
- 12.Which is the odd one out: 63, 27, 49, 81? (a) 63 (b) 27 (c) 49 (d) 81
- 13.Which is the odd one out: 24, 48, 22, 66? (a) 24 (b) 48 (c) 22 (d) 66
- 14.Which is the odd one out: 68, 40, 16, 80? (a) 68 (b) 40 (c) 16 (d) 80
- 15.Which is the odd one out: 64, 24, 96, 46? (a) 64 (b) 24 (c) 96 (d) 46
- 16.Which is the odd one out: 16, 26, 48, 24? (a) 16 (b) 26 (c) 48 (d) 24
- 17.Which is the odd one out: 18, 54, 12, 56? (a) 18 (b) 54 (c) 12 (d) 56
- 18.Which is the odd one out: 99, 81, 33, 27? (a) 99 (b) 81 (c) 33 (d) 27
- 19.Which is the odd one out: 48, 14, 24, 42? (a) 48 (b) 14 (c) 24 (d) 42
- 20.Which is the odd one out: 66, 40, 48, 80? (a) 66 (b) 40 (c) 48 (d) 80
- 21.Which is the odd one out: 62, 48, 96, 16? (a) 62 (b) 48 (c) 96 (d) 16
- 22.Which is the odd one out: 30, 48, 16, 32? (a) 30 (b) 48 (c) 16 (d) 32
- 23.Which is the odd one out: 64, 18, 32, 16? (a) 64 (b) 18 (c) 32 (d) 16
- 24.Which is the odd one out: 35, 81, 63, 45? (a) 35 (b) 81 (c) 63 (d) 45
- 25.Which is the odd one out: 42, 36, 54, 56? (a) 42 (b) 36 (c) 54 (d) 56
- 26.Which is the odd one out: 81, 49, 63, 27? (a) 81 (b) 49 (c) 63 (d) 27
- 27.Which is the odd one out: 16, 22, 24, 48? (a) 16 (b) 22 (c) 24 (d) 48
- 28.Which is the odd one out: 33, 99, 27, 81? (a) 33 (b) 99 (c) 27 (d) 81
- 29.Which is the odd one out: 54, 96, 24, 48? (a) 54 (b) 96 (c) 24 (d) 48
- 30.Which is the odd one out: 18, 48, 32, 16? (a) 18 (b) 48 (c) 32 (d) 16
- 31.Which is the odd one out: 32, 86, 40, 80? (a) 32 (b) 86 (c) 40 (d) 80
- 32.Which is the odd one out: 12, 48, 16, 10? (a) 12 (b) 48 (c) 16 (d) 10
- 33.Which is the odd one out: 49, 27, 81, 63? (a) 49 (b) 27 (c) 81 (d) 63
- 34.Which is the odd one out: 81, 65, 45, 27? (a) 81 (b) 65 (c) 45 (d) 27
- 35.Which is the odd one out: 56, 16, 42, 96? (a) 56 (b) 16 (c) 42 (d) 96
- 36.Which is the odd one out: 16, 82, 24, 48? (a) 16 (b) 82 (c) 24 (d) 48
- 37.Which is the odd one out: 66, 16, 64, 96? (a) 66 (b) 16 (c) 64 (d) 96
- 38.Which is the odd one out: 26, 32, 48, 96? (a) 26 (b) 32 (c) 48 (d) 96
- 39.Which is the odd one out: 27, 99, 81, 33? (a) 27 (b) 99 (c) 81 (d) 33
- 40.Which is the odd one out: 24, 96, 22, 88? (a) 24 (b) 96 (c) 22 (d) 88
Answer key
- 10
- 34
- 35
- 82
- 55
- 30
- 70
- 78
- 35
- 44
- 58
- 49
- 22
- 68
- 46
- 26
- 56
- 33
- 14
- 66
- 62
- 30
- 18
- 35
- 56
- 49
- 22
- 33
- 54
- 18
- 86
- 10
- 49
- 65
- 42
- 82
- 66
- 26
- 33
- 22
Free maths olympiad lessons, practice and worksheets at talentjr.in/maths-olympiad