# Quantitative Aptitude: Number Series Set 82

Directions(1-10):The following series are based on a certain pattern. One of the number in series is missing given by ?. Find that number.

1. 21, 11, 15, 40, 136.5, ?
618.75
543.25
576.75
634.15
None of these
Option A
Solution:
*0.5 + 0.5, *1.5 – 1.5, *2.5 + 2.5, *3.5 – 3.5, *4.5 + 4.5

2. 6, 11, 20, 38, 72, ?
176
131
126
143
145
Option B
Solution:
+5………..+9…………+18……….+34………..+59
…….+22…………+32…………+42………..+52

3. 18, 67, 31, 56, 40, ?
54
51
47
49
56
Option D
Solution:
+72, -62, +52, -42, +32

4. 18, 8, 10, 16, ?, 560
88
84
72
108
126
Option C
Solution:
*0.5 – 1, *1 + 2, *2 – 4, *4 + 8, *8 – 16

5. 456, 312, 481, 285, 510, ?
301
239
264
287
254
Option E
Solution:
-12, +13, -14, +15, -16

6. 4, 5, 12, 39, ?, 805
204
158
176
160
238
Option D
Solution:
*1 + 1, *2 + 2, *3 + 3, *4 + 4, *5 + 5

7. 15.2, 16.9, 20.3, 25.4, 32.2, ?
40.2
41.3
40.7
38.9
38.5
Option
Solution:
+1.7, +3.4, +5.1, +6.8, +8.5

8. 21, 24, 19, 28, 13, ?
26
36
23
38
40
Option B
Solution:
…+3…………-5………….+9………….-15………..+23 ……..+2……………+4………..+6…………..+8

9. 43, 47, 31, 67, ?, 103
3
5
11
8
14
Option A
Solution:
+22, -42, +62, -82, +102

10. 3, 5, 12, 38, 154, ?
708
662
698
772
736
Option D
Solution:
*1 + 2, *2 + 2, *3 + 2, *4 + 2, *5 + 2