Percentages at Work: Denominators and Percentage Points

Percentages at Work: Denominators and Percentage Points

Answer 15 questions randomly selected from a bank of 30. Choose one best answer per question. Pass with 12 correct answers. Original practice material, not an official certification exam.
1 of 15
Group A has 1 success in 2 attempts; group B has 9 in 10. What is the combined success rate?