Problems on Numbers
Q41. 6, 18, 3, 21, 7, 56, ?
(a) 8
(b) 10
(c) 12
(d) 15
Answer: (a) 8
1st Series : 6, 18, 3 ; 6 X 3 = 18
2nd Series : 3, 21, 7 ; 3 X 7 = 21
3rd Series : 7, 56, ? ; 7 X ? = 56 => ? = 56/7 = 8
Q42. 20, 20, 19, 16, 17, 13, 14, 11, ? ?
(a) 10, 10
(b) 11, 11
(c) 12, 13
(d) 14, 15
Answer: (a) 10, 10
Let the missing term be x1, x2
Now, 1st series : 20, 19, 17, 14, x1
2nd Series : 20, 16, 13, 11, x2
In Series 1 : 20 - 1 = 19, 19 - 2 = 17, 17 - 3 = 14, 14 - 4 = 10 ∴ x1 = 10
In Series 2 : 20 - 4 = 16, 16 - 3 = 13, 13 - 2 = 11, 11 - 1 = 10 ∴ x2 = 10
Q43. 2, 10, 40, 120, ?, 240
(a) 120
(b) 180
(c) 220
(d) 240
Answer: (d) 240
2 X 5 = 10
10 X 4 = 40
40 X 3 = 120
120 X 2 = 240
240 X 1 = 240
∴ The missing term is 240
Q44.
| 6, 9, 13 | 1 | , ? |
| 2 |
(a) 11 ½
(b) 15 ¼
(c) 20 ¼
(d) 21 ¼
Answer: (c) 20 ¼
| 6 X | 3 | = 9 |
| 2 |
| 9 X | 3 | = | 27 | = 13 | 1 |
| 2 | 2 | 2 |
| 13 | 1 | X | 3 | = | 27 | X | 3 | = | 81 | = 20 | 1 |
| 2 | 2 | 2 | 2 | 4 | 4 |
Q45. 4, 12, 36, 108, 324, ?
(a) 712
(b) 875
(c) 955
(d) 972
Answer: (d) 972
4 X 3 = 12
12 X 3 = 36
36 X 3 = 108
108 X 3 = 324
324 X 3 = 972
Q46. 1, 1, 2, 6, 24, ?, 720
(a) 98
(b) 120
(c) 340
(d) 520
Answer: (b) 120
1 X 1 = 1
1 X 2 = 2
2 X 3 = 6
6 X 4 = 24
24 X 5 = 120
120 X 6 = 720
Q47. 3, 10, 101, ?
(a) 896
(b) 990
(c) 999
(d) 10202
Answer: (d) 10202
32 + 1 = 9 + 1 = 10
102 + 1 = 100 + 1 = 101
1012 + 1 = 10202
Q48. 13, 35, 57, 79, 911, ?
(a) 997
(b) 1003
(c) 1113
(d) 1234
Answer: (c) 1113
1 - 3 = 13
3 - 5 = 35
5 - 7 = 57
7 - 9 = 79
9 - 11 = 911
11 - 13 = 1113
Q49. 3823, 4247, ?, 5242, 5824
(a) 4419
(b) 4579
(c) 4718
(d) 5052
Answer: (c) 4718
5824 - 582 = 5242
5242 - 524 = 4718
4718 - 471 = 4247
4247 - 424 = 3823
Q50. 6, 13, 25, 51, 101, ?
(a) 119
(b) 203
(c) 223
(d) 252
Answer: (b) 203
6 X 2 + 1 = 13
13 X 2 - 1 = 25
25 X 2 + 1 = 51
51 X 2 - 1 = 101
101 X 2 + 1 = 203
Practice Test Exam