Basic Ability Test Basic Ability Number Series and Sequences 4 — Questions and Answers
Question 1: What comes next in the alternating series: 1, 10, 2, 20, 3, 30, ___?
- 4 (Correct answer)
- 40
- 31
- 33
Correct answer: 4
Odd positions form 1,2,3,… so the next odd-position term is 4.
Question 2: Find the missing term: 3, 9, 27, 81, ___?
- 162
- 243 (Correct answer)
- 324
- 405
Correct answer: 243
Each term is multiplied by 3 (powers of 3), so 81 × 3 = 243.
Question 3: Complete the sequence: 17, 14, 11, 8, ___?
- 3
- 4
- 5 (Correct answer)
- 6
Correct answer: 5
Each term decreases by 3, so 8 − 3 = 5.
Question 4: What is the next number? 2, 4, 8, 14, 22, ___?
- 28
- 30
- 32 (Correct answer)
- 34
Correct answer: 32
Differences are 2, 4, 6, 8, 10 — increasing by 2 — so 22 + 10 = 32.
Question 5: Which value continues: 100, 50, 25, 12.5, ___?
- 5
- 6.25 (Correct answer)
- 7.5
- 10
Correct answer: 6.25
Each term is halved, so 12.5 ÷ 2 = 6.25.
Question 6: Find the missing number: 1, 2, 4, 7, 11, ___?
- 14
- 15
- 16 (Correct answer)
- 17
Correct answer: 16
Differences increase by 1 each step (1,2,3,4,5), so 11 + 5 = 16.
Question 7: What comes next in: 64, 32, 16, 8, 4, ___?
- 1
- 2 (Correct answer)
- 3
- 0.5
Correct answer: 2
Each term is divided by 2, so 4 ÷ 2 = 2.
Basic Ability Test Basic Ability Number Series and Sequences 4
What comes next in the alternating series: 1, 10, 2, 20, 3, 30, ___?