Probability with general multiplication rule

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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:

Grade	$10^{th}$ ‍	$11^{th}$ ‍	$12^{th}$ ‍
Number of students	$7$ ‍	$18$ ‍	$5$ ‍

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 $11^{th}$ ‍ graders?
Round your answer to two decimal places.

Precalculus

Course: Precalculus > Unit 8

Problem