What comes next in the following sequence? 20.25, 12.25, 6.25, 2.25, ?
2023
What comes next in the following sequence?
20.25, 12.25, 6.25, 2.25, ?
Answer: C. 0.25 — ConceptA sequence can be tested by comparing consecutive differences. If those differences change by a constant amount, the next difference continues that…
- A.
1.0
- B.
1.25
- C.
0.25
- D.
0
Attempted by 2 students.
Show answer & explanation
Correct answer: C
Concept
A sequence can be tested by comparing consecutive differences. If those differences change by a constant amount, the next difference continues that second-difference pattern.
Application
Calculate the consecutive differences: 12.25 − 20.25 = −8; 6.25 − 12.25 = −6; and 2.25 − 6.25 = −4.
The differences −8, −6, and −4 increase by 2 each time.
Continue that pattern: the next difference is −2, so the next term is 2.25 − 2 = 0.25.
Cross-check
The terms are also 4.52, 3.52, 2.52, and 1.52. Decreasing the base by 1 gives 0.52 = 0.25.
Result
The next term is 0.25.