Maths Olympiad Prep

Library / /424 of 475

, 2011

Combinatorics Difficulty 3.0 AMC 10/12 Find the answer Canada

An ordered list of four numbers is called a quadruple. A quadruple (p,q,r,s)(p, q, r, s) of integers with p,q,r,s0p, q, r, s \geq 0 is chosen at random such that 2p+q+r+s=42p + q + r + s = 4. What is the probability that p+q+r+s=3p + q + r + s = 3?

(A) 322\frac{3}{22} (B) 311\frac{3}{11} (C) 319\frac{3}{19} (D) 619\frac{6}{19} (E) 27\frac{2}{7}

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Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project. Solutions are the publisher's, linked not copied.