To gain entry into the strawberry fields, Sally, Jenny and Moses paid a total of 4 * 3 = <<4*3=12>>12 dollars
This means that before Miguel applied the $12 discount, the cost was 128 + 12 = <<128+12=140>>140 dollars
We get the weight by dividing the cost by the price of strawberries per pound, 140/20 = <<140/20=7>>7 pounds
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