Let the first and last terms of a sequence be ( 1 16 ) and 128
MATHEMATICS · Subjective · A Level · Mathematics · Sequences and series · Sequences and series
Problem
Let the first and last terms of a sequence be 161 and 128, respectively.
(i) Insert three numbers between them so that all five numbers are in geometric progression.
(ii) Write the fifth term of this geometric progression (counting 161 as the first term).
(iii) Calculate the product of the three inserted numbers and express it in simplest form.