Practice Questions: Classification- 1

Directions: In this type of questions, certain pairs/groups of numbers are given out of which all except one are similar in some manner while one is different. The numbers in these similar pairs/groups may have the same property or may be related to each other according to the same rule. The candidate is required to choose the odd pair/group.

Q1: Find the odd one out from the given alternatives:
(a) 7 - 26
(b) 5 - 31
(c) 9 - 32
(d) 8 - 29
Ans: (b)
7 × 3 = 21 + 5 = 26
5 × 3 = 15 + 5 = 20
9 × 3 = 27 + 5 = 32
8 × 3 = 24 + 5 = 29
Except (5 - 31), in every other pair the first number is first being multiplied by 3 and next added to 5 to give the resultant number.
Option B is hence the correct answer.

Q2: Select the one which is different from the other three responses.
(a) 8 - 11
(b) 1 - 4
(c) 7 - 10
(d) 3 - 5
Ans: (d)
From the options,
we get 1st option:   8 - 11 = 3
2nd option:   1  - 4 = 3
3rd option:   7  - 10 = 3 But
4th option:    3 - 5  = 2
Hence, fourth option is different.
Hence, option D is correct.

Q3: Select the one which is different from the other three responses.
(a) 68-25
(b) 71-28
(c) 59-43
(d) 51-32
Ans: (c)
Except (59 - 43), all other numbers subtractions' are odd.
68 - 25 = 43 |
71 - 28 = 43 | Odd numbers
51 - 32 = 19 |
but
59 - 43 = 16 | Even number
Hence, option C is correct.

Q4: Select the one which is different from the other three responses.
(a) (96, 24)
(b) (39, 18)
(c) (81, 54)
(d) (82, 64)
Ans: (d)
Except the number pair (82, 64), in all other number pairs both the numbers are multiples of 3.
96 = 32 × 3;    24 = 8 × 3
39 = 13 × 3;    18 = 6 × 3
81 = 27 × 3;    54 = 18 × 3
Hence, option D is correct.

Q5: Select the one which is different from the other three responses.
(a) 18 - 26
(b) 30 - 37
(c) 54 - 62
(d) 77 - 85
Ans: (b)
From the options, we get
1st option: 18 - 26 = 8
3rd option: 54 - 62 = 8
4th option: 77 - 85 = 8
But, 2nd option: 30 - 37 = 7
Hence, second option is different.
Hence, option B is correct.

Q6: Select the one which is different from the other three responses.
(a) 12 - 144
(b) 13 - 156
(c) 15 - 180
(d) 16 - 176
Ans: (a)
12 - 144
Second number is a perfect square of a first number.
Hence, option A is correct.

Q7: Select the one which is different from the other three responses.
(a) 82 - 73
(b) 66 - 58
(c) 26 - 17
(d) 55 - 46
Ans: (b)
Except pair (66 - 58), all other pairs' difference is 9.
82 - 73 = 9;
26 - 17 = 9;
55 - 46 = 9.
But 66 - 58 = 8.
Hence, option B is correct.

Q8: Select the one which is different from the other three responses.
(a) (108, 36)
(b) (56, 19)
(c) (42, 14)
(d) (69, 23)
Ans: (b)
Except the pair (56, 19), in all other pairs the first number is thrice the second number.
108 = 36 × 3, 42 = 14 × 3, 69 = 23 × 3
But 56 = 19 × 3 - 1.
Hence, option B is correct.

Q9: Select the one which is different from the other three responses.
(a) 4 - 16
(b) 2 - 17
(c) 7 - 11
(d) 5 - 19
Ans: (a)
Both the numbers in the pair 4 - 16 are perfect squares.
Hence, option A is correct.

Q10: Find the odd one out from the given alternatives:
(a) 45 -27
(b) 20 -13
(c) 15 -12
(d) 30 - 18
Ans: (b)
Except (20 - 13), all other pairs are multiples of 3.
Hence, option B is correct.