DIRECTIONS for the question 4-8: What should come in place of question mark (?) in the following number/alphabetic series

DIRECTIONS for the question 4-8: What should come in place of question mark (?) in the following number/alphabetic series

4. C – 3, E – 5, G – 7, I – 9, ?, ? 
   
   1. K – 11, M – 13
   2. O – 15, X – 24
   3. M – 18, K – 14
   4. X – 24, M – 21
   
   
   Answer & Explanation
   Answer: Option A
   
5. 5, 16, 51, 158, ? 
   
   1. 483
   2. 481
   3. 1454
   4. 1452
   
   
   Answer & Explanation
   Answer: Option B
   5 × 3 + 1 = 16
   16 × 3 + 3 = 51
   51 × 3 + 5 = 158
   158 × 3 + 7 = [481]

6. 9 × 2: 9 × 9 : : 9 × 5 : ? 
   
   1. 9 × 6
   2. 9 × 7
   3. 9 × 8
   4. 9 × 4
   
   
   Answer & Explanation
   Answer: Option A
   9×2=18
   9×9=81
   The digits of resultant have interchanged positions therefore,
   9×5=45
   9×6=54
7. AFI, JOR, MRU, ?
   
   1. HMP
   2. PMO
   3. RJL
   4. GJN
   
   
   Answer & Explanation
   Answer: Option A
   
8. bc, cde, de, efg, fg, ? 
   
   1. fgh
   2. hij
   3. ijk
   4. Gh
   
   
   Answer & Explanation
   Answer: Option D
   The answer should be the last alphabhet of fg ( i.e g ) and the next two alphabets i.e hi . Hence answer is ghi
   bc → cde → de → efg → fg → ghi