AMC 12 2000 Problem 20

Past Contests AMC 12 2000
, , ,
1

If x, y, and z are positive numbers satisfying

x+1 / y=4, \quad y+1 / z=1, \text { and } z+1 / x=7 / 3

then x y z=

Answer Choices
A. 2 / 3
B. 1
C. 4 / 3
D. 2
E. 7 / 3