A sexual health service followed two groups for one year. Each group used either condoms or a contraceptive implant as its main method of contraception. No participant had a diagnosed sexually transmitted infection at the start, and the groups reported similar patterns of sexual contact.
| Method | Number of participants | Number diagnosed with a new sexually transmitted infection |
|---|---|---|
| R | 150 | 3 |
| S | 300 | 18 |
Calculate the percentage of participants diagnosed with a new sexually transmitted infection for each method. Use your answers to explain which method was more likely to be condoms.
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.