Answer:
Dozen; A set of 12
4 dozen:- 4 x 12 = 48 glasses in total
5/12 of the 48 glasses are wasted
5/12 x 48 = 20 glasses are broken
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Work Shown:
1 dozen glasses = 12 glasses
4 dozen glasses = 48 glasses
48*(5/12) = 20 glasses are broken
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Alternative route:
5 glasses out of 12 are broken
This is the same as saying 5 glasses out of 1 dozen are broken.
Multiply both values by 4 to get 4*5 = 20 glasses broken out of 4*1 = 4 dozen.