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1.9 F: Exponentials and logarithms

1.9 F: Exponentials and logarithms

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Question 10

Two experiments measuring the population of insects are started at the same time. PA=ae0.2tP_A = ae^{0.2t}PA​=ae0.2t and PB=be0.15tP_B = be^{0.15t}PB​=be0.15t. At the start (t=0t=0t=0) total is 120. After 8 days (t=8t=8t=8) total is 480.

a.

Show that a=50a = 50a=50, to the nearest whole number, and find the value of bbb.

[3]
b.

Estimate the total number of insects after 10 days.

[1]
c.

Find the day that the number of insects in experiment A exceed the number of insects in experiment B.

[3]
Markscheme

1.9 F: Exponentials and logarithms Questions

  1. A Level
  2. /Maths
  3. /1.9 F: Exponentials and logarithms

62 exam-style questions on AQA A Level Maths 1.9 F: Exponentials and logarithms, covering 1.9.1 Exponential functions and their graphs, 1.9.2 Gradient of e^kx (A-level only), 1.9.3 Logarithms as inverse functions, 1.9.4 Laws of logarithms, 1.9.5 Solving exponential equations, 1.9.6 Logarithmic graphs to estimate parameters (A-level only), and 1.9.7 Exponential growth and decay. Each one has a worked solution and a mark scheme showing where the marks go.

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