The wide cupboard holds twice as many glasses as the tall cupboard, amounting to 20 * 2 = <<20*2=40>>40 glasses.
Each of the shelves in the narrow cupboard holds 15 / 3 = <<15/3=5>>5 glasses.
Since a shelf was broken, a narrow cupboard now holds only 15 – 5 = <<15-5=10>>10 glasses.
In total, there are 20 + 40 + 10 = <<20+40+10=70>>70 glasses.
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