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Probability with general multiplication rule

AP.STATS: VAR‑4 (EU), VAR‑4.D (LO), VAR‑4.D.2 (EK), VAR‑4.E (LO), VAR‑4.E.1 (EK), VAR‑4.E.2 (EK) CCSS.Math: HSS.CP.A.2, HSS.CP.B.8
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Problem

Rosalyn is a teacher who plays a review game with her class. The game involves writing each student's name on an identical slip of paper and selecting students at random. Here's the makeup of her class:
Grade10, start superscript, start text, t, h, end text, end superscript11, start superscript, start text, t, h, end text, end superscript12, start superscript, start text, t, h, end text, end superscript
Number of students7185
Suppose that Rosalyn wants 2 different students, so she picks 2 names without replacing names between picks.
What is the probability that both students selected are 11, start superscript, start text, t, h, end text, end superscript graders?
Round your answer to two decimal places.
  • Your answer should be
  • an exact decimal, like 0, point, 75
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