The heights (in cm) of steps in a newly built staircase form an arithmetic…
MATHEMATICS · Single correct · A Level · Mathematics · Sequences and series · Sequences and series
Problem
The heights (in cm) of steps in a newly built staircase form an arithmetic progression: the first step is 18 cm high, and each successive step is 0.5 cm shorter than the previous one. Steps are built until a step height of 15 cm is reached or crossed. Which statement about the resulting sequence of step heights is correct?
(a) Finite AP with 6 terms
(b) Not an AP because the common difference changes
(c) Finite AP with 7 terms
(d) Finite AP with 8 terms