Number Series MCQs set 2 for ISSB - Pak Army Officer Selection intelligence — 20 solved questions.
Q1. Next: 9, 18, 36, 72, ?
Answer: 144
Explanation: Each term doubles. 72 times 2 equals 144. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q2. Next: 11, 22, 33, 44, ?
Answer: 55
Explanation: The series increases by 11. 44 plus 11 equals 55. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q3. Next: 5, 6, 8, 11, 15, ?
Answer: 20
Explanation: Differences are 1, 2, 3, 4, so next is 5. 15 plus 5 equals 20.
Q4. Next: 2, 4, 7, 11, 16, ?
Answer: 22
Explanation: Differences are 2, 3, 4, 5, so next is 6. 16 plus 6 equals 22.
Q5. Next: 100, 95, 89, 82, ?
Answer: 74
Explanation: Differences are -5, -6, -7, so next is -8. 82 minus 8 equals 74.
Q6. Next: 3, 5, 9, 17, ?
Answer: 33
Explanation: Pattern: times 2 minus 1. 17 times 2 minus 1 equals 33.
Q7. Next: 1, 2, 6, 24, ?
Answer: 120
Explanation: Multiply by 2, 3, 4, 5. 24 times 5 equals 120. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q8. Next number: 2, 5, 11, 23, ?
Answer: 47
Explanation: Pattern doubles and adds 1 so 23 times 2 plus 1 is 47.
Q9. Next number: 1, 3, 6, 10, 15, ?
Answer: 21
Explanation: Triangular numbers add 2,3,4,5,6 so next is 21. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q10. Next number: 4, 8, 16, 32, ?
Answer: 64
Explanation: Each term doubles so next is 64. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q11. Next number: 7, 14, 28, 56, ?
Answer: 112
Explanation: Each term doubles so next is 112. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q12. Next number: 100, 95, 90, 85, ?
Answer: 80
Explanation: Subtract 5 each step so next is 80. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q13. Next number: 3, 9, 27, 81, ?
Answer: 243
Explanation: Multiply by 3 each time so next is 243. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q14. Next number: 10, 20, 40, 80, ?
Answer: 160
Explanation: Each term doubles so next is 160. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q15. Next number: 3, 8, 15, 24, ?
Answer: 35
Explanation: Add 5,7,9,11 so next add 11 gives 35. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q16. Next number: 1, 4, 27, 256, ?
Answer: 3125
Explanation: Powers 1^1,2^2,3^3,4^4 so next is 5^5 equals 3125. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q17. Next number: 6, 11, 21, 36, 56, ?
Answer: 81
Explanation: Second differences constant add 5,10,15,20,25 gives 81. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q18. Next number: 9, 18, 36, 72, ?
Answer: 144
Explanation: Each term doubles so next is 144. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q19. Next number: 5, 6, 8, 11, 15, ?
Answer: 20
Explanation: Add 1,2,3,4,5 so next is 20. Work each step carefully; ISSB math rewards accuracy under time pressure.
Q20. Next number: 4, 9, 19, 39, ?
Answer: 79
Explanation: Pattern doubles and adds 1 so 39 times 2 plus 1 is 79.