Select the number from among the given options that can replace the question…
2024
Select the number from among the given options that can replace the question mark (?) in the following series.
23, 27, 43, 79, 143, ?
- A.
240
- B.
243
- C.
250
- D.
200
Attempted by 21 students.
Show answer & explanation
Correct answer: B
Calculate differences:
27 - 23 = 4 (2²)
43 - 27 = 16 (4²)
79 - 43 = 36 (6²)
143 - 79 = 64 (8²)
Identify pattern: The differences are squares of consecutive even numbers: 2², 4², 6², 8².
Calculate next term: The next even number squared is 10² = 100. Add this to the last term: 143 + 100 = 243.
Final Answer: Option 2