Skip to content

Course home

3.3 Sequences and series (A-level only)

3.3 Sequences and series (A-level only)

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149
Question 108

A subscription-based fitness app tracks the number of new premium users each month. In the first three months after a major update, the number of new premium users, in thousands, was recorded as:

3k−28,k,k+6 3k - 28, \quad k, \quad k + 6 3k−28,k,k+6

where kkk is a constant. Given that the number of new users joining each month is modeled as a geometric series,

a.

show that k2−5k−84=0k^2 - 5k - 84 = 0k2−5k−84=0.

[3]
b.

Predict the number of new premium users joining in the 6th month.

[2]
c.

The total number of all premium users who have joined the app since the update is predicted to exceed 5 million for the first time in the NNNth month.

Calculate the value of NNN according to the model.

[4]
Markscheme

3.3 Sequences and series (A-level only) Questions

  1. A Level
  2. /Maths
  3. /3.3 Sequences and series (A-level only)

200 exam-style questions on CCEA A Level Maths 3.3 Sequences and series (A-level only), covering 3.3.1 Sequences and series (A-level only), 3.3.2 Sequences and series (A-level only), 3.3.3 Sequences and series (A-level only), 3.3.4 Sequences and series (A-level only), 3.3.5 Sequences and series (A-level only), 3.3.6 Sequences and series (A-level only), 3.3.7 Sequences and series (A-level only), and 3.3.8 Sequences and series (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

Question bank