From the give information, 15/28 of the writing utensils are black pens
From the question, we are to determine what fraction of the writing utensils are black pens
From the give information,
5/7 of the writing utensils are pens
and
3/4 of the pens are black pens
∴ 3/4 of 5/7 of the writing utensils are black pens
3/4 of 5/7 = 15/28
Hence, 15/28 of the writing utensils are black pens
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