Crossover Aptitude Numerical Reasoning: Number Sequences Questions and Answers — Questions and Answers
Question 1: What is the next number in the following sequence? 3, 7, 16, 35, 74, ...
- 148
- 153 (Correct answer)
- 158
- 162
Correct answer: 153
The pattern is to multiply the previous number by 2 and then add an increasing integer (1, 2, 3, 4, ...). 3 * 2 + 1 = 7. 7 * 2 + 2 = 16. 16 * 2 + 3 = 35. 35 * 2 + 4 = 74. Therefore, the next number is 74 * 2 + 5 = 153.
Question 2: Identify the missing number in the sequence: 8, 12, __, 27, 37.5
- 15
- 16
- 18 (Correct answer)
- 21
Correct answer: 18
This is a geometric sequence where each subsequent number is the previous number multiplied by 1.5. 8 * 1.5 = 12. 12 * 1.5 = 18. 18 * 1.5 = 27. 27 * 1.5 = 40.5 (Correction: The last number should be 40.5 for the pattern to hold, but with 37.5 the closest consistent pattern is x1.5). Let's re-evaluate based on the provided options. 8 * 1.5 = 12. 12 * 1.5 = 18. 18 * 1.5 = 27. 27 * 1.5 = 40.5. The number 37.5 in the sequence seems to be a typo, but the only logical step from 12 to 27 is multiplying by 1.5, which gives 18.
Question 3: Which number completes the sequence? 1, 1, 2, 3, 5, 8, 13, __
- 20
- 21 (Correct answer)
- 22
- 24
Correct answer: 21
This is a Fibonacci sequence, where each number is the sum of the two preceding ones. 1 + 1 = 2. 1 + 2 = 3. 2 + 3 = 5. 3 + 5 = 8. 5 + 8 = 13. The next number is 8 + 13 = 21.
Question 4: A project's task completion rate follows the sequence: 2, 6, 14, 30, 62. What is the next number in this completion sequence?
- 124
- 126 (Correct answer)
- 128
- 130
Correct answer: 126
The pattern is to multiply the previous number by 2 and then add 2 (or 2^(n+1) - 2). 2 * 2 + 2 = 6. 6 * 2 + 2 = 14. 14 * 2 + 2 = 30. 30 * 2 + 2 = 62. Therefore, the next number is 62 * 2 + 2 = 126.
Question 5: Find the next number in the alternating sequence: 3, 10, 8, 12, 13, 14, 18, __
- 16 (Correct answer)
- 18
- 20
- 23
Correct answer: 16
This is an alternating sequence. There are two independent sub-sequences. The first is 3, 8, 13, 18 (add 5 each time). The second is 10, 12, 14 (add 2 each time). The next number belongs to the second sub-sequence, so it is 14 + 2 = 16.
Question 6: What is the next number in the two-tier sequence: 2, 3, 6, 11, 18, 27, ...?
- 36
- 38 (Correct answer)
- 40
- 42
Correct answer: 38
This is a two-tier sequence where the difference between the numbers forms a simple arithmetic progression. The differences are: 3-2=1, 6-3=3, 11-6=5, 18-11=7, 27-18=9. This sequence of differences (1, 3, 5, 7, 9) is an arithmetic progression of odd numbers, increasing by 2 each time. The next difference will be 11. Therefore, the next number in the main sequence is 27 + 11 = 38.
What is the next number in the following sequence? 3, 7, 16, 35, 74, ...