Ich habe morgen einen Statistik Test und bräuchte dringend eure Hilfe bei 3 Aufgaben, bei denen ich nicht auf den Lösungsweg komme. Ich wäre unheimlich froh, wenn mir jemand kurz die den Lösungsweg erklären könnte.

Vielen Dank schon mal im Voraus!
LG
Question 5
A student prepares for an exam by studying a list of ten problems. She finds she can ONLY solve six of these problems. For the exam, the lecturer selects five problems at random from the ten on the list given to the students. What is the probability that the student can solve all five problems in the exam? (Assume this student’s ability to solve problems in statistics does not change between preparing for and writing the exam!)
A. 0.600 B. 0.024 C. 0.500 D. 0.833 E. 0.114
Question 9
Three names are to be selected from a list (alphabetical) of seven names for a public opinion survey. Find the probability that the first name on the list is selected for the survey?
A. 0.410 B. 0.143 C. 0.429 D. 0.857 E. 0.600
Question 10
Suppose that two defective refrigerators have been included in a shipment of six refrigerators. The buyer (who does not know how many defective refrigerators are in the shipment) begins to test the six refrigerators one at a time. He will reject the lot if he finds two defectives. What is the probability that no more than four refrigerators need to be tested to locate both of the defective refrigerators? [Assume that the refrigerators are indistinguishable from each other except in terms of whether or not they are defective]
A. 0.875 B. 0.400 C. 0.333 D. 0.600 E. 0.933