【Question 4】
If $a, b, c, d$ are distinct positive integers, and $a \times b \times c \times d=357$, then $a+b+c+d=$ $\qquad$
【Analysis and Solution】
Decompose 357 into prime factors: $357=3 \times 7 \times 17$; so breaking down 357 into the product of four distinct positive integers can only be $357=1 \times 3 \times 7 \times 17$; that is, $\{a, b, c, d\}=\{1,3,7,17\}$;

The sum of these four numbers is $1+3+7+17=28$.