We know x1<7<x3<11<x5
x1∈1,2,3,4,5,6
x3∈8,9,10
x5∈12,13,14,15,16,17,18
Required probability P=C518C16×C13×C17=681
Five numbers x1,x2,x3,x4,x5 are randomly selected from the numbers1,2,3,……,18 and are arranged in the increasing order (x1<x2<x1<x4<x2). The probability that x2=7 and x4=11 is
Held on 27 Jun 2022 · Verified 6 Jul 2026.
1361
681
687
685
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