She has used 32 ounces on 8-ounce glasses because 4 x 8 = 32
She has used 30 ounces on the 5-ounce glasses because 6 x 5 = 30
She has used 62 ounces in total because 32 + 30 = <<32+30=62>>62
She has 60 ounces left because 122 - 62 = <<122-62=60>>60
She can fill fifteen four-ounce glasses because 60 / 4 = <<60/4=15>>15
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