A bag contains n white and n black balls. Pairs of balls are drawn at random without replacement successively, until the bag is empty. If the number of ways in which each pair consists of one white and one black ball is 14400 , then n is eq

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A bag contains n white and n black balls. Pairs of balls are drawn at random without replacement successively, until the bag is empty. If the number of ways in which each pair consists of one white and one black ball is 14400 , then n is equal to

Quantrex Academy · Accepted Answer

Correct answer: B. 5

According to the given condition ( ^n C₁ ^n C₁ ) ( ^ n-1 C₁ ^ n-1 C₁ ) ( ^1 C₁^1 C₁ )=14400 aligned & ( ^n C^ n-1 C₁ ^1 C₁ )^2=(120)^2 & n(n-1)(n-2) 1=120 & n !=5 ! & n=5 & aligned

A bag contains n white and n black balls. Pairs of balls are drawn at random without replacement successively, until the bag is empty. If the number of ways in which each pair consists of one white and one black ball is 14400 , then n is equal to

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