In a cookie jar there are 9 sugar cookies and 12 snickerdoodle cookies. The cookie are randomly mixed together in the jar. What is the probability of pulling two of the same types of cookies out of the cookie jar in a row without replacement?

Agroup of student volunteers participates in a study designed to assess several behavioral interventions for improving output in a repetitive task. prior to the beginning of the study, all volunteers unknowingly observed, and their output is measured. at the beginning of the study, prior to any intervention, the volunteers perform the same task under the observation of a study administrator, and their overall output increases. which of the following terms describes this phenomenon? a. simpson's paradox b. hawthorne effect are d. novelty effect d. pygmalion effect e. observer-expectancy effect