# From a bag containing 60 standard and 40 substandard articles, two articles are chosen at random.

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From a bag containing 60 standard and 40 substandard articles, two articles are chosen at random. What is the probability that one of them is standard and the other substandard?

(a) $\frac{60}{100}\times \frac{40}{100}$

(b) $\frac{60}{100}\times \frac{39}{100}$

(c) $\frac{16}{33}$

(d) 24%

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(c) $\frac{16}{33}$

Here two articles are chosen together without replacement

P(one of the articles is substandard) = P (first article is standard) × P(second article is substandard) + P (first article is substandard) × P (second article is standard)

$\frac{60}{100}\times\frac{40}{99}$ + $\frac{40}{100}\times\frac{60}{99}$

$\frac{4800}{9900}$ = $\frac{48}{99}$ = $\frac{16}{33}$