Three integers from the list have a product of 80. What is the sum of these three integers?
Solution
The three integers from the list whose product is 80 are 1, 4, and 20, since . The sum of these integers is .
(Since 80 is a multiple of 5 and 20 is the only integer in the list that is a multiple of 5, then 20 must be included in the product. This leaves two integers to choose, and their product must be . From the given list, these integers must be 1 and 4.)
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