Three integers from the list $1,2,4,8,16,20$ have a product of 80 . What is the sum of these three integers?
(A) 21
(B) 22
(C) 25
(D) 29
(E) 26
The three integers from the list whose product is 80 are 1,4 and 20 , since $1 \times 4 \times 20=80$.

The sum of these integers is $1+4+20=25$.

(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 $\frac{80}{20}=4$. From the given list, these integers must be 1 and 4 .)

ANSWER: (C)