An advice service compares two contraceptive methods. The table shows their effectiveness during one year of typical use.
| Method | Effectiveness |
|---|---|
| contraceptive injection | 94% |
| condom | 82% |
The service models what would happen if 250 people used each method for one year.
A person seeking advice wants to minimise the chance of pregnancy, often forgets to take tablets every day and needs protection from sexually transmitted infections. An adviser recommends using the contraceptive injection on its own.
Calculate the difference between the expected number of pregnancies for the two methods in the model.
Evaluate the adviser’s recommendation.
90 exam-style questions on Edexcel GCSE Biology 7.2 Reproductive hormones, covering 7.2.1 Stages of the menstrual cycle, 7.2.2 Hormonal control of the menstrual cycle, 7.2.3 Hormonal contraception, 7.2.4 Evaluating contraception methods, and 7.2.5 Hormones in Assisted Reproductive Technology. Each one has a worked solution and a mark scheme showing where the marks go.