GMA Number Series 2 — Questions and Answers
Question 1: What is the next number in the series: 3, 6, 12, 24, 48, ?
- 72
- 96 (Correct answer)
- 84
- 64
Correct answer: 96
Each term is doubled: 3×2=6, 6×2=12, 12×2=24, 24×2=48, 48×2=96.
This is a geometric series with a common ratio of 2. Each term is multiplied by 2 to get the next term. Starting from 3: 3, 6, 12, 24, 48, 96. Geometric series with ratio 2 are among the most common patterns in GMA numerical reasoning tests.
Question 2: Find the missing term: 81, 27, 9, ?, 1
- 6
- 4
- 3 (Correct answer)
- 2
Correct answer: 3
Each term is divided by 3: 81÷3=27, 27÷3=9, 9÷3=3, 3÷3=1.
This is a decreasing geometric series with a common ratio of 1/3 (or equivalently, each term is divided by 3). The sequence is 81, 27, 9, 3, 1. The missing term is 3. Recognising that the ratio between terms is constant — and less than 1 — is the key insight.
Question 3: What comes next in the series: 1, 4, 9, 16, 25, ?
- 30
- 34
- 36 (Correct answer)
- 40
Correct answer: 36
These are perfect squares: 1²=1, 2²=4, 3²=9, 4²=16, 5²=25, 6²=36.
The series 1, 4, 9, 16, 25 is the sequence of perfect squares (n²). The differences between terms are 3, 5, 7, 9 — consecutive odd numbers — which is another way to confirm the pattern. The 6th term is 6²=36. Perfect-square series appear frequently in GMA number pattern tests.
Question 4: Complete the series: 2, 3, 5, 8, 13, 21, ?
- 29
- 31
- 34 (Correct answer)
- 35
Correct answer: 34
This is the Fibonacci sequence where each term equals the sum of the two preceding terms: 13+21=34.
The Fibonacci sequence is defined by F(n) = F(n-1) + F(n-2). Starting with 2 and 3: 2, 3, 5 (2+3), 8 (3+5), 13 (5+8), 21 (8+13), 34 (13+21). This pattern is widely used in GMA tests to assess whether candidates can identify recursive additive relationships.
Question 5: Find the next number: 100, 91, 82, 73, 64, ?
- 56
- 55 (Correct answer)
- 54
- 53
Correct answer: 55
Each term decreases by 9: 100-9=91, 91-9=82, 82-9=73, 73-9=64, 64-9=55.
This is an arithmetic series with a common difference of -9. Starting at 100 and subtracting 9 repeatedly yields 100, 91, 82, 73, 64, 55. The common difference can be confirmed by checking any two consecutive terms (e.g., 73-64=9).
Question 6: What is the missing number: 2, 6, 18, ?, 162
- 48
- 54 (Correct answer)
- 62
- 72
Correct answer: 54
Each term is multiplied by 3: 2×3=6, 6×3=18, 18×3=54, 54×3=162.
This geometric series has a common ratio of 3. Multiplying each term by 3 generates the sequence 2, 6, 18, 54, 162. The missing fourth term is 18×3=54. Verifying by dividing 162÷3=54 confirms the answer.
GMA Number Series 2
What is the next number in the series: 3, 6, 12, 24, 48, ?