What is the next number in the sequence 99, 80, 63, 48, 35, 24, ... ?
Answer and explanation
Correct answer: C. 15
- Step 1: Add 1 to each term: 100, 81, 64, 49, 36, 25, which are 10², 9², 8², 7², 6² and 5². Step 2. The next square is 4² = 16, and subtracting 1 gives 15. Answer: 15. Why not the others: 14: This is one less than the pattern, 4² - 2. 16: This is 4² and does not subtract 1. 13: This subtracts 11, repeating the last gap instead of taking the next one.
Practise more Number sequences and patterns.
Free questions with an explanation for every one, and full timed Independent School Entrance (ISEB Pre-Test and 11+ CEM style) mock tests.
More Number sequences and patterns questions
- What is the next number in the sequence 4, 13, 28, 49, 76, 109, ... ?
- What is the next number in the sequence 5, 12, 21, 32, 45, 60, ... ?
- What is the next number in the sequence 2, 6, 12, 20, 30, 42, ... ?
- What is the next number in the sequence 1, 3, 7, 15, 31, 63, ... ?
- What is the next number in the sequence -1, 5, 15, 29, 47, 69, ... ?
- What is the next number in the sequence 3, 15, 35, 63, 99, 143, ... ?