Probability with balls

Hello,

In box there are (n) white balls, (m) black balls and (k) red balls. Balls is drawn from box one after another. Then is written everyone ball color. What is the probability that white color in written list will be shown earlier than black.

Maybe, n/(n+m) ?

123 said:

In box there are (n) white balls, (m) black balls and (k) red balls. Balls is drawn from box one after another. Then is written everyone ball color. What is the probability that white color in written list will be shown earlier than black.

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It is not clear from that description if the balls are replaced after each draw or not replaced. That small fact changes the question greatly.