Answer: Option D
The series is: -15, -30, - 45, -60
So the answer is: 100

Answer: Option A
The series is: 20 23 29 40 58 85
3 6 11 18 27
3 5 7 9
Answer is 23

Answer: Option B
5*1+2=7
7*2+3=17
17*3+4=55
55*4+5=225
225*5+6=1131
Answer is 1131

Answer: Option A
10 6 8 15 34
(10/2 +1)*1=6
(6/2+1)*2=8
(8/2+1)*3=15
(15/2+1)*4=34
(17+1)*5=90
Answer is 90.

Answer: Option E
The series is: 85 53 33 22 17 15
32 20 11 5 2
12 9 6 3
Answer is 15.

Answer: Option C
Here the series follows as 2^2, 4^2, 6^2, and so on. So the term will be 12^2 = 144

Answer: Option C
Clearly, the first, the second and the third letters of each term are moved two, three and four steps forward respectively to obtain the corresponding term. So, the next term will be G R X

Answer: Option D
Here the first letter of each term is moved two step backward to get the first letter of next term. So for missing term, it will be M
The second letter of 1st, 2nd and 3rd terms are respectively moved one, two and three steps forward to obtain the corresponding letter of next term. So, for missing term it is G. The third letter of each term is moved one step forward to get next term. Thus, third letter of missing term is N. Hence, the answer becomes MGN

Answer: Option E
a, z, ab, y, abc, x, abcd, w…next will be abcde.
So, the next alphabet will be 'e'
Hence, the correct answer is option E

Answer: Option D
There are two alternate series in the following arrangement
A B B D C F D H E J
Thus the next term will be F. Hence option D is the answer .