Problem: For every triple (a,b,c) of non-zero real numbers, form the number
∣a∣a+∣b∣b+∣c∣c+∣abc∣abc
The set of all numbers formed is
Answer Choices:
A. {0}
B. {−4,0,4}
C. {−4,−2,0,2,4}
D. {−4,−2,2,4}
E. none of these
Solution:
If a,b and c are all positive (negative), then 4 (respectively, -4) is formed; otherwise 0 is formed.