A lab technician needs 20 liters of a solution that is 17% acid for a certain experiment, but she has only a solution that is 10% acid and a solution that is 30% acid. How many liters of the 10% and the 30% solutions should she mix to get what she needs?

When analyzing tree rings, what do scientists assume a thin ring indicates?

Is there any solid scientific evidence that humans have been cloned?

Which best describes the scientific method? a. a path of clearly defined steps that must be followed in a particular order b. a possible answer to a scientific question based on knowledge or research c. the recipe for how to conduct an experiment that must be followed precisely d. the process of hypothesis and testing through which scientific inquiry occurs